In the last few months:
- Tumblr purged adult content (and a bunch of stuff it misindentified).
- Flickr purged free storage above a limit of 1000 photos/account.
- Myspace deleted 12 years’ worth of music.
And Google+ has less than two weeks left before Google pulls the plug on it.
Back up your social media accounts! Most sites have some sort of archive utility, and even if what you get isn’t suitable for moving to another site, at least you’ll have a copy in case they change their business model, screw up a data migration, get washed away in a flood or just shut down.
And if you can, consider donating to the Internet Archive to help protect other sites you rely on or would just like to see again. Websites go offline every day. Sometimes even the big ones.