When does healthy skepticism become full-blown paranoia?

[unicron44]

It a question I've been pondering recently. I've heard the phrase "question everything" before and it's good to be skeptical but sometimes I feel people take way too far.

When do you feel this line is crossed?

 

[Hal10k]

At the point where a statement can be prefaced with "Dude, what if..." without the essential meaning being altered.

 

[Ordinaryundone]

I guess when it starts to seriously effect your relationships and interactions with other people? Its one thing to believe the government is watching you or something, its another to not make friends because your afraid of them being jerks.