You have to remember that the Cambridge city council also declared the city to be a nuclear free zone, as well.
If I recall correctly, Cambridge opened their city offices at 12:01 a.m. on the day homosexual marriage was allowed in Massachusetts. They wanted to show how liberal they are and perform the first legalized homosexual marriages.
The irony is, that if radical Muslims gain any foothold in America, that the people they would go after first are the liberals. The liberals who are the most accomodating towards Islam are considered the biggest enemies of Islam.