For the record, I only ever earned 350 points (200 on Choice Privileges and 150 on PCR), and I got the warning e-mail.

Best I can figure, the only remotely suspicious thing I did on Foursquare is check-in at two eligible hotels in one day (over a year ago). If that's the new Topguest standard for cheating, it's going to catch people (like me) who attend large conventions that spread events between multiple hotels. (I was at Gen Con Indy.)

Anyway, Starwood is partnering directly with Foursquare as of today, which is an example of the real reason Topguest is doomed. Now that most of Foursquare's competitors are dead, there's very little reason for loyalty programs to bother with a middleman company.