Foursquare is making a minor tweak to the service in the hopes to spur more engagement with every check-in you make. Now, people can like your check-ins, even if they aren't friends with you on Foursquare.
Let's say you shared a check-in on Twitter, and someone clicked through to Foursquare. Even if you aren't connected, they'll be able to interact with your post.
"Starting today, when you share your #braggybrag check-ins with friends on Twitter or Facebook who are on Foursquare, they’ll be able to like them, even if they’re not your Foursquare friends. We’ll even send you a notification so you know how awesome you are (you can turn them off in your settings)," says Foursquare.
All you have to do to turn off these notifications (if you don't care when non-friends like your stuff) is head to your notifications settings. About halfway down the page, you'll see the option to turn on/off email and text notifications "when someone who isn't a friend likes or saves my activity."
A small, but interesting update from Foursquare, who is always looking to boost engagement with check-ins (that's what makes it operate more like a true social network, after all).