Is it the right balance though? I am pretty sure they're using GCHQ to do this. In fact when Newsnight first covered it, they had a spokesman for GCHQ defending it, and of course one of the reasons he gave was paedophilia,
It sounds like a good reason, so I know why he said that. However, stopping paedophiles is not a national security issue. It isn't the job of the intelligence services to do forensics, it is the job of the police. Using the capability of GCHQ I'm sure would help them find paedophiles quite quickly. it would help them find evidence quite quickly, the problem is, we have laws protecting us from suspicionless surveillance like this from the police.