Ironically, many card subjects come to interpret this state of affairs in a contra view (the card helps streamline my dealings with authority, rather than the card is my license to deal with authorities). The Australia Card campaign referred to the card as a license to live.

The above is from the ID Cards FAQ by Privacy International. Highly recommended reading, for the sake of us all.

A more fundamental question:
Why doesn't the UK dump IWF and censorship?

Why should we hope to have 'appropriate' censorship, or hope that censor 'mistakes' can be 'corrected'? When we accept censorship as a tool 'for the common good', and get caught in Byzantine discussions about which speech/'content' is more or less 'harmful' and should be less or more free (instead of adopting a simpler view like the one in the US First Amendment), we are already sliding down a very steep, very slippery slope.

Although not a censorship system per se, it ends up being useful for government-mandated filtering policies (at national or institutional levels) based on ratings by locally blessed (or treaty-sanctified) rating institutions. Political power, bad journalism, and others systematically protesting against the internet as 'the new wild west' repeatedly claim that 'something should be done' to prevent spreading of 'misinformation' (in contrast to 'reference' content) and, ultimately, the infocalypse.

Always beware government abuse of any tools and standards, however useful they may seem at first. As with risks of massive private data archives, hoping standardized ratings systems won't be misused for censorship purposes seems like hoping that water won't wet...