The Hutaree arrest was based on nothing more than a bull session in the woods that was inspired by a federal informant. In fact if you’ve ever read the report, that bull session was tamer than things we regularly see posted here at FR.
http://www.freerepublic.com/focus/f-news/3005940/posts
The feds accused them of plotting a simultaneous attack on police all across southeastern Michigan and northwestern Ohio. In the end they possessed no explosives and apparently never sought them or could be conned into buying any.
People wouldn't have the slightest clue they have the makings for a WMD in their possession.
A terrorist could be anyone.
Just like with the Hutaree, they can target you at will.