I find this kind of thing very worrying, for two main reasons:
1. Scope creep. Anti-terrorism legislation is already used to stop peaceful protest; just because the current government says this monitoring is only about crime doesn’t mean that the next one won’t find more inventive uses for it.
2. Commercial use: in 10 years time facial and gait recognition will be capable of detecting when you park your car, the route you took to the cinema, the restaurant you stopped at, and the time you took to get back to your starting point. That kind of information is massively valuable to advertisers, insurance companies, etc. What’s going to stop a future government from selling that data?