I’m reading that this is a specific “whitelist” super-kid-friendly (in theory) filter, not the default web filter.
http://pseudomonas.dreamwidth.org/120535.html
There are three levels of blocking:
Open Access - what people who’ve asked for “no filtering at all” see.
Default Safety - what people who’ve signed up without expressing preferences see.
Parental Control - what people who’ve actively asked for a child-friendly device see.
Now, O2’s Parental Control is a funny old thing. It allows http://www.mcdonalds.com but blocks http://www.childline.org. To be honest, it blocks most of the internet apart from a tiny number of mostly corporate sites. It allows amazon.co.uk but blocks amazon.com. We may never know why - this is all done by their unspecified third-party partner (rumour has it that this is probably Symantec).
So, don’t feel too proud, BoingBoing hasn’t been specifically called out, it just hasn’t been included.
Edit: as other people are saying, this is also a mobile-specific filter, not broadband.