Look, I title my WiFi networks weird things all the time, just because I know strangers will see it and be confused. Some are great wordplay, some are simply bizarre non-sequitors, some of them are downright disgusting, and some are deliberately misleading.
My hunch is that this network is NOT that of an actual FBI surveillance van, but the product of a fun-loving person setting up their router.
That said, it would be pretty simple to use wifi sniffing tools to pinpoint the source of the signal and actually, you know, VERIFY this absurd claim.
I mean, the feds are stupid, but I don't think they're THAT stupid.