Big Head DC is hearing that security is being stepped up a notch at 400 North Capitol Street in preparation for a controversial appearance by conservative squawker Ann Coulter, who will be a guest on “Hardball” this evening in a rare outdoor live audience session.

Coulter has been pied before and apparently MSNBC has received credible threats that cream-decked cronies plan on doing it again — and hopefully on live TV.

This is one of the first majorly-hyped live audience appearances Coulter has made since calling John Edwards the f*g word in March.