That's an in-house complaint before the FTC's own judge. I'm talking about a request for a preliminary injunction in Federal district court in front of a real judge. The FTC doesn't have the authority to block a transaction unless they're in an Article III court; their in-house proceedings can only unwind a transaction after it closes.
Well, you asked if the FTC did anything and they definitely did something. What credit they can claim for the eventual outcome is a different discussion but the answer to 'did they do anything' appears to be 'yes'.
Sorry, I should have made clear I meant "do anything to block the merger." That's what my reference to a preliminary injunction was about, but I realize this is a tech forum and not a law forum so I should have clarified.
The FTC's action certainly deters behavior. You don't need an actual court order and armed marshalls.