The irony in this whole thing is that people like the OP are precisely why NDAs should not be signed. When you are a company like foursquare, ideas like swarm a

The irony in this whole thing is that people like the OP are precisely why NDAs should not be signed. When you are a company like foursquare, ideas like swarm arise naturally from product evolution. Sure, you may have had the same idea 4 years ago but 4 years ago, it could have been a terrible idea. This brings me to my second point: OP is highly underestimating the importance of timing. It's akin to someone telling you everyday that you need to get treated for cancer; and then years later when you do get cancer, claiming he was right all along.