According to Fox News:
A 44-year-old Muslim convert says it was news to him that the flag he hung outside his house is the same banner waved by the murderous jihadist group known as Islamic State.
Neighbors and passersby who took to Twitter were alarmed at the black flag emblazoned with the Arabic words “The only god is Allah” flying from above the porch of Mark Dunaway, in Garwood, N.J. The chilling banner flew next to a red flag of Islam, but Dunaway said he never intended to show support for the terrorist group infamous for beheading Christians.
“I hang it every Friday and every Ramadan which ended not too long ago and I keep it up a little longer than I normally do,” Dunaway told FoxNews.com. “I guess some people saw it and got offended so I took it down. I do not support any militant group or anything like that.”
http://www.foxnews.com/us/2014/08/14/nj-man-says-isis-flag-flown-on-porch-misunderstanding/
So the police can make me remove a flag (any flag) from my home? Oh well, the 1st Amendment was okay while it lasted.
An “appropriate reaction” would be to burn the house to the ground.