The Feds are just BS'ing on this, there are pictures of those people all over the internet.
With all the technology, unlimited funds, and facial recognition stuff they have access to they could probably locate the majority of those people that were caught on camera within the next week or two.
You got amateurs on the internet that have already identified several of the people, so you telling me the most sophisticated law enforcement and investigation agency in the world can't do it. Nah this is just posturing.
This isn't of high priority to them despite them doing this to make it look otherwise.