“Liking” on Facebook has always aggregated itself, and you don’t feel the least bit sneaky when you catch your friends doing it. It’s a central part of the system. I can’t help but think, though, that liking — an explicitly public action — has always been repressed by its visibility. Unlike Twitter’s winking “atta girl” favorites, Facebook likes imply spread and advertisement. To like is to rebroadcast, which changes — maybe taints? — the things you like.
If everything you say you like is up for public review then you may find yourself changing the things you say you like.