Actually, it's not rediculous for England. After centuries of corrupt kings and even a dictatorship, it is a symbol of what they stand for. Charles I stormed Parliment in 1642 to arrest members of the oppostition group. He was eventually tried for treason and executed. IN the United States members cannot be arrested on the House or Senate floor (I believe).
See post 150 and thanks to the poster who posted it.
I think I was applying "Ridiculous" to the person who said Hastert should slam the door and then open it to them.
The Constitution is silent on where they can be arrested. It states what they can be arrested for and for some of what they cannot, namely anything they say in debates, or write into laws. Thus the term "Speech and Debate" clause, used to refer to that part of Article I, Section 6 of the Constitution.