I think this is a great, great shame. 
Argument A: "I couldn't see the subscription disclaimer at the bottom of the screen as it went too fast." - Er, don't sign up to these things if you can't see the small print. Idiot.
Argument B: "It was an under 16 who signed up. How were they to know?" - Er, if they didn't know about these 'complex' things, should they really be in possesion of a mobile phone. No, doufuss.
It's a great shame the ASA have sided with the idiots taken in by the Idiot Tax. Let's hope other forms of non-TV advertising can still mean these poor people can get their (horrid) ringtones, so we all know that they're idiots when they're walking down the street with their phones on.
Give them a wide berth - they might do something stupid!
(Apologies if this has offended you, friend. Jamster will still take your money, if you want them to? That's good - I'm glad you've got money to burn. I'll do a little dance once every week, just for you, if you forward £10 in cash to: [insert my address]. That's right, one little dance, every week - just send £10 in cash to: [insert my address].)