this license is pissing me off, read my Contracts post Everybody Knows Peggy Lee (or should) which explains what's implied by license wording such as the above -- regardless of whether it's couched in language that says "We only want these rights so we can perform the service." Further Addendum: Check out the comments below for more addenda -- I'm posting updates as people feed them to me, and it's easier to add a comment than to edit the post over and over. Another further Addendum: I've got a new post talking about the factors in selecting an off-site backup service, the basics of data security, and discussing some alternatives to dropbox. Find it here . Yet Another Addendum: There are more updates on the Dropbox situation at my new blog post here . Final Addendum: As mentioned at the beginning of this post, Dropbox has taken everyone's outrage seriously, and has fixed the problem. More information here . Looks like they've softened the wording yet again, adding in clarifying comments about what they mean by derivative work. Too late to get me to change my verdict, but if you're interested in this mess, do be sure to click on the link to the TOS to see what it says at the moment -- at the time of this comment, it seems to be changing every half-hour or so, probably in response to people writing them to complain. Except that there's an earlier line in the same TOS that says