I have several moles, 2 moderately active, 1 extremely active. All have far exceeded 5k posts, serve on juries, members of MIRT, 1 a former Host. They post mostly innocuous subjects and in places like the Lounge, C&B, other minor forums. The active one is all over LBN and GD agreeing heartily with the latest drama in long prose with flowery detail. It's turned into a creative writing exercise.
I said they had reason to be paranoid only because if they think they have reason to be paranoid they're ignorant enough to reap the benefits of paranoia.
I've edited to say that all these moles joined years ago. Most joined before I ever knew about CU (learned of CU from a Yahoo user named GoreBites), much less CC. It was just something I did to pass time when bored. I didn't even know the terminology for what I was doing at first.