I'd say that CCTV is quite different to wiretapping. You (generally) wouldn't have the expectation of privacy in a public place, most people would expect that phone calls, messages, etc do remain private.
Now, GCHQ is no better than the NSA for that either, but I don't think CCTV is a good comparison.
By comparison America is actually quite timid compared to other countries e.g. UK and the widespread CCTV network.