BREAKING NEWS? Police action in Portland?

Reports have come in from the Munjoy Hill area near Kennedy Park that there are at least 7 police cars prowling in the area, plus a black helicopter circling with someone looking out the side. Any ideas, folks?

UPDATE:
I just received the following information from a reader via our Google Groups postings that seems to explain a bit:

There is a giant sign near my work that says "homeland Security Drill". I work near the Casco Bay Ferry area.