I haven't heard anything, but i think it a wise choice for Americans to stay out for a while.

here in Birmingham, i have taken to talking in low tones, mummbling, or whispering in Mayhem's ear whilst we are out and about town. My accent is like a neon sign above my head saying "Look at me, I am an American" Before the 7th of July, i spoke aloud, with out a care. But now i am careful, and what few words i say aloud, like "thank you", i have been working on the British accent. I am not scared, just careful.