They happen all of the time, presumably due to the success of Bitcoindark.  That was the exception rather than the rule.  I placed a very modest investment into DarkPeerCoin right after the ICO because I read the entire thread and liked the interaction from the dev.  Yeah, it didn't work out at all.  Coins that name themselves after established projects should be interacted with caution.

That said, I'm loving Swift and the development.  The next year is going to be amazing in crypto development and user experience.  Speculative pump days might be nearing an end based on the strength of dev teams here and elsewhere which aren't easily copied.