The possibility of them blowing stuff up is not the main reason to be wary of importing large numbers of Muslims from areas of the world where Islam is extreme in its conservatism. Rather, it is as was stated in the New York Times cite:
Trevor Phillips, the former chairman of the Equality and Human Rights Commission, analyzed the results for Channel 4 and said in a statement that they showed Britain faced a threat of βthe establishment of a nation within our nation.β