> They know people will feel kinda embarrassed to call their ISP and say "I want porn"

I called my Canadian cable company on some trivial matter. The end of the call went something like: "We've got a great deal on the kids TV channel package. Do you want to sign up?"

"I live by myself. Not interested."

"Oh, in that case, I can give you a deal on our adult channels."

Moral of the story: the call centre staff couldn't care one way or the other - they're just doing their jobs. Call 'em up and get the stupid filter removed.