That's awful and the most amazing thing you could do now is get together with those ex-coworkers or similar people and compete with Google in whatever business domain it was that made them acquire your former employer.

Because, having been through the acquisition process at Google myself, my general cynical take is: Google acquires companies to get rid of them, to stop them from competing and not to "add your uniqueness to their collective."

Keeping employees on retention bonuses is a way, in aggregate, of stopping them from going off and inventing something that eats their bottom line.

You should look into legal action. And failing that, compete with them.