Is it possible to crawl check-in data from foursquare in a greedy way? (even if I don't have friendship with all the users) Just like crawling publicly available twitter messages. If you have any experience or suggestions, please share. Thanks.
If you have publicly available tweets containing links to foursquare, you can resolve the foursquare short links (4sq.com/XXXXXX) by making a HEAD request. The head request will return a URL with a check-in ID and a signature. You can use those two values to retrieve a check-in object via the foursquare API /checkins/ endpoint. You're only allowed to access 500 of these per hour.
You must abide by both the Twitter and foursquare terms of service -- in fourquare's case, you may not display this information to anyone, nor may you retain any user information for more than 3 hours (since the user has not authorized your application).
You can only get the check-in data for a location if the manager of the location gives you OAuth access to your application. If you have that, you can use the real-time API defined here: https://developer.foursquare.com/docs/realtime.html
No, it is not possible to crawl check-in data similar to Twitter. This information is considered personal data and is not public.
You can crawl twitter data for foursquare data =)
来源：https://stackoverflow.com/questions/8206849/how-to-crawl-foursquare-check-in-data