Facebook sat in stasis for years without innovating their products. Now they are using their incumbent position to steal every single snapchat feature with impunity.
Of course that's par for the course in tech. Where the giant companies throw their weight around to crush competition.
Will there be an antitrust suit?
Copying ideas is 3/4 of tech nowadays, whether it's a website design and features, or a social network, or a cab-hailing app (Uber, Lyft, etc etc).
I think this is a good thing, because it allows creativity and competition within established ideas, instead of letting whoever came up with it first have a monopoly on it.
Heck, I almost developed and released something almost identical to Pintrest before Pintrest came out. Good thing I didn't -- and wasn't allowed to claim some kind of rights on the idea -- because my version would have sucked. (Well, sucked in a different way from Pintrest does.)
It also sets a very poor precedent for entrepreneurial people.
In fact, it's one of the few instances of capitalism actually working the way it "works" on paper.