EXHIBIT 4

Case 6:20-cv-00309-ADA Document 41-4 Filed 08/26/21 Page 1 of 6
JEFFREY J. CATALANO

Partner

Freeborn & Peters LLP

Attorneys at Law

311 South Wacker Drive

Suite 3000

Chicago, IL 60606

(312) 360-6832 direct

(312) 360-6520 fax

jcatalano@freeborn.com

www.freeborn.com

Chicago, IL • New York, NY • Richmond, VA • Springfield, IL • Tampa, FL

August 6, 2021

VIA EMAIL

Cecil E. Key

DIMUROGINSBERG, P.C.

1101 King St. 610

Alexandria, Virginia 22314

Re: Corrino Holdings LLC v. Expedia, Inc. et al

 6:20-cv-00309-ADA (W.D.Tex.)

Counsel:

We write on behalf of Defendants Expedia, Inc. and trivago N.V. (“Defendants”) to address Corrino 

Holdings LLC’s (“Corrino”) Amended Infringement Contentions, dated August 3, 2021 

(“supplemental infringement contentions”), and accompanying Exhibits A-G. We note that Corrino 

made minor additions and changes to its contentions but that many of the deficiencies identified in 

our June 23, 2021, letter persist in the supplemental contentions.

We write to address certain fatal defects, without limitation as to the other deficiencies identified in 

the June 23, letter. We request a meet and confer prior to Wednesday, August 11 to see if we can 

reach an agreement. Should we fail to agree, Defendants intend to move to strike Corrino’s 

infringement contentions with respect to asserted U.S. Patent Nos. 9,152,734 (the “’734 Patent”),

7,716,149 (the “’149 Patent”), and 6,741,188 (the “’188 Patent”), for at least the reasons detailed 

below:

Exhibit F - the ’734 Patent

Corrino’s supplemental infringement contentions confirm that the accused flight search results 

interface does not infringe the asserted claims of the ’734 Patent, and several claim limitations are 

either not addressed by the supplemental contentions or are not plausible under any claim 

construction (or both).

No User-Submitted Stories

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Corrino’s supplemental infringement contentions are crystal clear that the “users” of the Accused 

Instrumentalities are those individuals that access and search the accused websites seeking flight 

information. See e.g. Ex. F at 1 (“Expedia allows users to search flights...”), 2 (“Expedia enables 

users to search query for available flight options”). Flight search results are contended to satisfy 

the various “story” or “stories” requirements of the claim.

However, the method of Claim 1 requires “accessing a plurality of stories....each story submitted by 

a user.” There is no allegation in the supplemental infringement contentions that flights, flight 

information, or flight search results are “submitted by a user.” See Ex. F. at 4-5. Indeed, such an 

allegation is not plausible, as Expedia and the other Accused Functionalities do not rely on users of 

the website to upload or submit flight schedules, flight pricing information, or the like.

No User-Provided Indication That the Remaining Story is Associated with the Same One or More 

Participants

Similarly, there is nothing in the supplemental infringement contentions that would support the 

conclusion that “each remaining story is associated with an indication provided by one or more 

users that the remaining story is associated with the same one or more participants.” Corrino 

contends that “Expedia filters the results associated with the different airlines (‘more participants’) 

based on criteria indicating user preferences.” But the contentions do not point to any indication 

provided by one or more users nor can Corrino plausibly supplement their contentions to do so. To 

the extent the operating airline can be assumed to meet the “participant” limitation, there is no 

indication provided by the user associating the flight search result [story] with a participant [airline]. 

Expedia and the other Accused Functionalities do not rely on users to indicate that Flight 101 is 

operated by Delta (for example).

No Calculation of the Relative Importance of Each Story in the Intersection Space

Corrino’s supplemental infringement contentions further demonstrate that the Accused 

Functionalities do not meet the limitation of “calculating relative importance of each story in the 

intersection space, wherein the relative importance indicates a relative overlap between the 

timeframe of interest and a timeframe of the respective story.” Corrino’s contentions confirm that 

no relative importance is calculated, instead each flight search result displayed in the alleged 

“intersection space” have a 100% overlap between the “timeframe selected by the user and departure 

time of each airline story in the search result.” Exhibit F at 8. Moreover, despite stating that “the

results are displayed based upon the calculated relative importance” the documentation cited in the 

supplemental contentions prove that this is false. “The Sort settings at the top of the page allow you 

to order search results to your preference, such as price, verified review score, and other criteria.” 

Exhibit F at 8. The image pasted on the subsequent pages shows flight results ordered not by 

calculated relative importance but by earliest departure time (Page 9) and price (Page 10). 

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Exhibit B - the ’149 Patent

Corrino’s supplemental infringement contentions confirm that the trivago’s Hotel Manager does not 

infringe the asserted claims of the ’149 Patent, and several claim limitations are either not addressed 

by the supplemental contentions or are not plausible under any claim construction (or both). Further, 

Corrino’s position stretch the claims of the ’149 Patent to cover basic link tracking and reporting, a 

technology that predates the ’149 Patent by a substantial number of years before the alleged 2006 

priority date.

Failure to Plausibly Identify a “Persistent Virtual Environment”

Corrino’s supplemental infringement contentions still appear to state that the “persistent virtual 

environment” of Claim 1 is the “Trivago Hotel Manager [that] facilitates hotel profiles (“persistent 

virtual environment”) and is a platform that enables a user to take control of a Hotel’s profile...”). 

Ex. B at Page 1. As the grammar of this allocation makes clear it is still the Trivago Hotel Manager 

that “is a platform that enables a user to take control of a Hotel’s profile.” Given the ’149 Patent’s 

disclosure as to “persistent virtual environment,” there is no conceivable construction of the term in 

which the trivago Hotel Manager would satisfy this limitation. 

Perhaps the supplemental contentions are attempting to refer to some unspecified hotel information 

that includes links to the booking page of hotels, as the viewer’s interaction with these links are later 

asserted to be social aspects within the persistent virtual environment. Assuming for the sake of 

argument that this is correct, Corrino must supplement its contentions to properly point to what 

exactly is the persistent virtual environment that is also consistent with the assertions regarding the 

remaining elements of the claims.

Failure to Set Forth a Visualization that Represents a Social Aspect of the Alleged Persistent Virtual 

Environment

If as Corrino asserts, the trivago Hotel Manager application is the claimed “persistent virtual 

environment,” Corrino has not identified “a visualization that represents a social aspect of said 

persistent virtual environment” as required by Claim 1. As annotated on Page 4, Corrino maintains 

that the ability to “View the number of users redirected to your booking page from trivago” shows 

the “social aspect ... by number of viewers visiting the hotel website.” Given the ’149 Patent’s 

disclosure as to the term “social aspect,” there is no conceivable construction of the term in which a 

server redirecting a browser to a booking page would satisfy this limitation.

Even assuming arguendo that page views or redirects demonstrate a “social aspect” or “overall 

activity level,” this visualization does not show a social aspect of the Hotel Manager application 

itself (the claimed persistent virtual environment). Similarly, data on number of clicks in trivago's 

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search engine related to particular hotel does not show a social aspect of the Hotel Manager 

application itself.

Exhibit A - the ’188 Patent

No Dynamic Updating

As stated in our June 23, 2021 letter: 

Although the 188 Contentions stated in a conclusory fashion that “[a]s the 

user location changes the identified hotels are also dynamically updated” this 

assertion is not supported by the screenshots pasted into the contention charts. 

As patentee explained to the Patent Office during prosecution of the 188 

Patent, “dynamically updating” requires more than merely updating the 

current position for a subsequent query by a user or even automatically 

updating the search results based on change of location. 

Corrino did not update its contentions with respect to dynamic updating, other than to add a footnote 

that states “‘The linked information is ... dynamically updated’ is a software limitation and source 

code review is required to provide more detailed contentions.” See e.g., Ex. A at 10. Although the 

question of whether updating is dynamic rather than automatic may require a source code review, 

nothing in the infringement contentions would suggest that the search results are even updated 

automatically or without user interaction (such as re-running the search). The images pasted do not 

suggest dynamic or automatic updating, rather than separate searches in different locations. The 

allegations with respect to Expedia show search results in different perspectives in two very separate 

locations—Jersey City, NJ and Glendale, New York—more than an hour drive apart. The 

contentions with respect to Cheaptickets purport to show “dynamic updating” through screenshots in 

Chicago, Illinois and Washington D.C. The contentions with respect to Travelocity purport to show 

dynamic updating through screenshots in Miami, Florida and Washington, D.C. Also, remarkably, in 

each of the above examples the paired screenshots purportedly evidencing dynamic updating are

taken from different search platforms (website vs. app), so it is not clear how these images could 

possibly demonstrate dynamic updating of a single search result.

Did anyone on Corrino’s legal team run a “hotels nearby” search on (for example) the triage app, 

drive a mile down the road, and check the application to see if the search results were automatically 

updated? Based on Corrino’s contentions, we believe it highly unlikely that even this most basic

investigation was conducted. Please explain Corrino’s investigation with respect to “dynamically 

updated” for each of the accused applications Absent a compelling explanation, Defendants 

reserve the right to seek sanctions under Rule 11, 28 U.S.C. § 1927, or other similar provision.

* * * 

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Unless Corrino agrees to withdraw its claims of infringement with respect to these three patents, we 

intend to file a motion to strike no later than Friday, August 13. Please provide your availability for 

a meet and confer as soon as possible prior to close of business on Thursday, August 12.

Very truly yours,

Jeffrey J. Catalano

CC: Counsel of Record

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