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UNITED STATES DISTRICT COURT

WESTERN DISTRICT OF TEXAS

AUSTIN DIVISION

VOXER, INC. and VOXER IP LLC,

Plaintiffs

v. 

META PLATFORMS, INC. f/k/a 

FACEBOOK, INC. and 

INSTAGRAM LLC, 

Defendants

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CASE NO. A-20-CV-00655-LY-SH

ORDER DENYING META PLATFORMS, INC.’S

MOTIONS TO EXCLUDE EXPERT TESTIMONY

Before the court in the above styled patent-infringement action are, inter alia, Defendant 

Meta Platforms, Inc.’s (“Meta”) motion to exclude expert reports and opinions of Plaintiff Voxer, 

Inc. and Voxer IP LLC’s (collectively, “Voxer”) technical expert, Michael Mitzenmacher.1 Meta 

argues that Mitzenmacher’s opinions are conclusory, not based on sufficient facts or data, not 

based on any reliable principles or methods, and will not help the trier of fact to understand the 

evidence. See Fed. R. Civ. P. 702. Additionally, Meta challenges Voxer’s damages expert Alan 

Ratliff’s opinions about what would be a reasonable royalty award.2 Id. Meta asserts several 

1 The filings associated with this contention are [Meta’s] Revised Motion to Exclude Testimony by Voxer’s 

Technical Expert [ ] and Revised Motion to Strike [ ] Mitzenmacher’s Opinions on Literal and Doctrine of 

Equivalents Infringement That Voxer Failed to Disclose in Its Infringement Contentions filed January 28, 

2022 (Doc. #189), Voxer’s Revised Response In Opposition to Defendants’ Motion [ ] and Motion to Strike 

filed January 31, 2022 (Doc. #204), and Meta’s reply filed February 1, 2022 (Doc. #211). The 456-page 

Opening Expert Report is a sealed exhibit located in the case file at Document No. 190-1 (“Mitzenmacher’s 

Report”).

2 The filings associated with this contention are [Meta’s] Revised Motion to Exclude the Expert Reports 

and Testimony of Alan Ratliff filed January 28, 2022 (Doc. #185), Voxer’s Revised Response in Opposition 

to Defendants’ Motion to Exclude the Expert Reports and Testimony of Alan Ratliff filed January 31, 2022 

(Doc. # 136); and Meta’s reply filed February 1, 2022 (Doc. # 213). The 60-page Damages Expert Report 

of Alan Ratliff on Behalf of Voxer, Inc and Voxer IP LLC is a sealed exhibit located in the case file at 

Document No. 185-3 (“Ratliff’s Report”).

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reasons that Ratliff’s damages opinions fail to meet the essential requirement for reliability, which 

is that “the ultimate reasonable royalty award [ ] be based on the incremental value that the patented 

invention adds to the end product.” Commonwealth Sci. & Indus. Research Org. v. Cisco Sys., 

Inc., 809 F.3d 1295, 1301 (Fed. Cir. 2015). 

Accused Products: Facebook Live and Instagram Live

Voxer alleges that Meta infringes the patents-in-suit through the use of Meta’s products, 

Facebook Live and Instagram Live. Meta’s description of its product, Facebook Live, explains 

that Facebook Live was launched around December 3, 2015 and allows users to “broadcast in realtime a conversation, live performance, or virtual event.” Meta monetizes Facebook Live three 

ways: (1) Facebook places in-stream ads into the videos and shares the revenue from those ads 

with the content creators; (2) Facebook takes a portion of users’ direct payments to the live-content 

creators; and (3) Facebook charges content creators to boost their live content. Ratliff estimated 

that during the relevant time period, United States revenue from these sources directly tracked to 

Facebook Live exceeded $100 million. Meta’s description of Instagram Live explains that the 

two products are similar but have differences; for example, Instagram Live does not have a live 

rewind feature. Instagram Live does allow users to share real-time video broadcasts with one 

another. Meta monetizes Instagram Live differently, in that it does not offer in-stream ads. 

Voxer maintains that Meta’s revenue analysis is too limited in that it comprises only the 

new revenue channels created by Facebook Live and does not account for the increased appadvertising revenues resulting from all Live video watch time. Because Meta does not track such 

data, Voxer asserts that Ratliff had to make such computations using Ratliff’s own model, which 

was based on the evidence produced during discovery. 

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Expert testimony

A witness qualified as an expert may testify if: 

the expert’s scientific, technical, or other specialized knowledge will 

help the trier of fact to understand the evidence or to determine a fact 

in issue; the testimony is based in sufficient facts or data; the testimony 

is the product of reliable principles and methods; and the expert has 

reliably applied the principles and methods to the facts of the case. 

FED. R. EVID. 702. Rule 702 was amended to incorporate the principles articulated in Daubert v. 

Merrill Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). See FED. R. CIV. P. 702, Adv. Comm. 

Notes (2000). Following Daubert and its progeny, trial courts act as gatekeepers, overseeing the 

admission of scientific and nonscientific expert testimony. See Kumho Tire Co. v. Carmichael, 

526 U.S. 137, 147 (1999). Trial courts must make “a preliminary assessment of whether the 

reasoning or methodology underlying the testimony is scientifically valid and of whether that 

reasoning or methodology properly can be applied to the facts in issue.” Daubert, 509 U.S. at 

592-93. In carrying out this task, district courts have broad latitude in weighing the reliability of 

expert testimony for admissibility. See Kumho Tire Co., 526 U.S. at 152. The district court’s 

responsibility “is to make certain that an expert, whether basing testimony upon professional 

studies or personal experience, employs in the courtroom the same level of intellectual rigor that 

characterizes the practice of an expert in the relevant field.” Id. 

Daubert provides the analytical framework for determining whether expert testimony is 

admissible under Rule 702 of the Federal Rules of Evidence. See Kumho Tire Co., 526 U.S. at 

141. This Daubert framework includes many factors that can be used to determine the 

admissibility of expert testimony, including, but not limited to, whether the expert’s theory or 

technique: (1) can be or has been tested; (2) has been subjected to peer review and publication; 

(3) has a known or potential rate of error or standards controlling its operation; and (4) is generally 

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accepted in the relevant scientific community. See Daubert, 509 U.S. at 593-94. Not every 

Daubert factor will be applicable in every situation and a court has discretion to consider other 

factors it deems relevant. See Kumho Tire, 526 U.S. at 151-52. 

Under these rules, a district court may exclude evidence that is based on unreliable 

principles or methods, legally insufficient facts and data, or where the reasoning or methodology 

is not sufficiently tied to the facts of the case. Kumho Tire, 526 U.S. at 150 (gatekeeping inquiry 

must be tied to particular facts of case); i4i Ltd. v. Microsoft Corp., 598 F.3d 831, 854 (Fed. Cir. 

2010) (“Daubert and Rule 702 are safeguards against unreliable or irrelevant opinions, not 

guarantees of correctness.”). Whether the expert is credible or the opinions are correct is 

generally a question for the fact finder, not the court. Apple Inc. v. Motorola, Inc., 757 Fed. Cir. 

1286, 1314 (Fed. Cir. 2014), overruled en banc on other grounds, Williamson v. Citrix Online, 

LLC, 792 F.3d 1339, 1349 (Fed. Cir. 2015). “Vigorous cross-examination, presentation of 

contrary evidence, and careful instruction on the burden of proof are the traditional and appropriate 

means of attacking shaky but admissible evidence.” Daubert, 509 U.S. at 596. 

To prove infringement, a plaintiff must prove the presence of each and every claim element 

or its equivalent in the accused method or device. Uniloc USA, Inc. v. Microsoft Corp., 632 F.3d 

1292, 1301 (Fed. Cir. 2011). Expert testimony is admissible to give an opinion on the ultimate 

question of infringement. Snellman v. Ricoh Co., Ltd., 862 F.2d 283, 287 (Fed. Cir. 1988); see 

also Star Scientific, Inc. v. R.J. Reynolds Tobacco Co., 655 F.3d 1364, 1378 (Fed. Cir. 2011) 

(plaintiff’s primary evidence in support of infringement claims was its technical expert’s 

infringement testimony and jury had ability to credit or discredit expert witness at trial). 

Meta’s motion asserts various reasons why the court should strike several portions of 

Mitzenmacher’s technical analysis. See Fed. R. Evid. 703. Meta also takes issue with Ratliff’s 

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damages opinions about what a reasonable royalty would be in the event the jury finds 

infringement. See 35 U.S.C. § 284. Meta does not take contest either Mitzenmacher’s or 

Ratliff’s qualifications. 

Challenges to Mitzenmacher’s report

Meta argues, inter alia, that Voxer has failed to demonstrate that Mitzenmacher’s technical 

apportionment opinions are the product of a reliable methodology and based on sufficient facts 

and data. Meta contends that Mitzenmacher’s opinions related to Instagram’s 2012 technology 

should be excluded because he only personally used Instagram for purposes of this litigation. 

Meta also argues that Mitzenmacher’s opinions regarding nontechnical matters should be excluded 

because the evidence shows that Mitzenmacher is not qualified to offer an opinion about the 

commercial acceptability of Facebook’s non-infringing alternatives and is not “an expert in the 

field of user privacy and data control.” Meta argues that Mitzenmacher’s opinions about 

Facebook’s state of mind as related to indirect infringement should be excluded because those 

opinions “amount to nothing more than vouching for Voxer’s allegations, which is improper.” 

Initially, the court finds that Mitzenmacher is a well-educated and qualified scientist. 

Mitzenmacher’s work, teaching, and research experience in the scientific fields related to the issues 

raised in the case reasonably indicate to the court, operating in a gatekeeping capacity, that 

Mitzenmacher is qualified to render opinions in this action based on his “knowledge, skill, 

experience, training, or education.” Fed. R. Civ. P. 702. The court finds that based on the 

flexible nature of the court’s Daubert inquiry, the issues raised by Meta may be explored and 

developed at trial through cross-examination of Mitzenmacher. The court thus concludes that 

Mitzenmacher’s opinions are relevant and may aid the jury. The court also concludes that 

Mitzenmacher may testify about his opinions related to whether Meta’s products infringe the 

patents at issue, and Meta may cross-examine Mitzenmacher regarding his methods. 

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Challenges to Ratliff’s report

Meta argues that Ratliff’s damages calculation should be excluded because the royaltybase portion of the calculation failed to use the Smallest Salable Patent Practicing Unit and instead 

improperly used the entire market value. “Where methodology is reasonable and its data or 

evidence are sufficiently tied to the facts of the case, the gatekeeping role of the court is satisfied, 

and the inquiry on the correctness of the methodology and of the results produced thereunder 

belongs to the factfinder.” Summit 6, LLC v. Samsung Elecs. Co., 802 F.3d 1283, 1296 (Fed. Cir. 

2015). Although apportionment generally is required if the patented features are not the sole 

driver of demand, it is not a rigid rule, but rather an evidentiary tool intended to avoid jury 

confusion. See, e.g., Ericsson, Inc. v. D-Link Sys., Inc., 773 F.3d 1201, 1226 (Fed. Cir. 2014) 

(“The point of the evidentiary principle is to help the jury system reliably implement the 

substantive statutory requirement of apportionment of damages to the invention’s value.”). 

Initially, the court in a gatekeeping capacity finds that Ratliff is well-educated and is 

qualified to testify about damages in this case. Having considered all of Meta’s contentions that 

portions of Ratliff’s report and his proposed testimony are deficient and should be excluded from 

trial, the court finds that Meta’s complaints are for the factfinder to assess. Cross-examination 

and the presentation of contrary evidence are the traditional and appropriate means of addressing 

what one side may believe to be shaky evidence. Daubert, 509 U.S. at 596. Meta may crossexamine Ratliff at trial about his methodology. 

Having considered Meta’s motions, the responses, the reply, each side’s supplemental 

authorities, the case file, and the applicable law,

IT IS ORDERED that [Meta’s] Revised Motion to Exclude Testimony by Voxer’s 

Technical Expert [ ] and Revised Motion to Strike [ ] Mitzenmacher’s Opinions on Literal and 

Doctrine of Equivalents Infringement That Voxer Failed to Disclose in Its Infringement 

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Contentions filed January 28, 2022 (Doc. #189) and [Meta’s] Revised Motion to Exclude the 

Expert Reports and Testimony of Alan Ratliff filed January 28, 2022 (Doc. #185) are DENIED. 

SIGNED August 16, 2022.

SUSAN HIGHTOWER

UNITED STATES MAGISTRATE JUDGE

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