It may be necessary, but it’s still illegal.
It is not necessary. Irrational fear is the rule here.
It’s not even necessary. Links below show how the Israelis handle flight security without molesting your wives, daughters and mothers.
http://www.thestar.com/iphone/news/world/article/744199-—israelification-high-security-little-bother
http://en.wikipedia.org/wiki/Airport_security