My impression is that it is pretty difficult to get a Rule 11 decision against a plaintiff.

I'm not an in-court civil litigator, and I will defer to them (I don't believe conor is a federal court civil litigator), but I've managed a fair number of federal litigations (as the client), and the courts seem to bend over backwards to entertain the craziest arguments. The bar is set quite low. The courts clearly lean towards "access to the courts" and away from punishing frivolous lawsuits. Until we get "loser pays" this will always be a problem. Rule 11 seems to solve maybe 10-20% of cases I would call frivolous. Just my impression. I would welcome a federal civil litigator to comment.