If an ISP chooses to force people to call in to modify their filter level that's their prerogative, but the government hasn't required that and as far as I know all ISPs currently have it handled through their website(s). For example my ISP BT just has it as a clickable option in the account management panel, here's a screenshot: http://i.imgur.com/dWxORfJ.png
That was the most amusing (and scaring) screenshot that I've seen in a while. No popular Facebook joke/Reddit meme ever made me chuckle that hard.
So .. you actually can tell your ISP that you're more into alcohol and nudity, but dislike porn? Tasteless would be nice, though?
I wonder if they wouldn't be more helpful if they'd just take the list of keywords/categories from YouPorn so that you can express your preferences in a better and more specific way..
Aren't we going in circles? If they can make it that easy to opt out, why not make it that easy to opt in? Isn't the whole premise that it's too hard and you can't expect normal people to opt in to a porn filter?