Feds always attend in plain clothes so this effectively does nothing. I also wonder if a Fed only means investigative or law enforcement type Feds or also includes federally employed IT peoples.
iamtherockstar you are hellbanned. Your comment appears as dead. I tell you because you made an informative comment. Looks like it happened about a month ago.
I don't think the intention is to create a moat around the conference. Things have been getting quite cozy between these two [1]; I'm sure recent revelations don't play well with this conference's attendee base.