If you are one of those who favours privacy laws, to protect people against being snooped on, you might want to make sure you aren’t asking the government to make operations like this one illegal.
That link was in David Carr’s Samizdata piece yesterday, and there’s more comment from him and from the Samizdata comment pack.

I imagine the exposure of fraud (and othe crime) might be allowed as a public interest defense.
Quite so, but you can easily imagine a world in which any attempt at such surveillance would have to be successful in order to avoid legal penalties. That would make such activities, even aimed at people who were guilty, less likely even to be attempted.
Mostly I despise the Sun, but this operation deserves praise for exposing Fearon as being anything but crippled.
I agree with the point about privacy laws needing careful drafting — a public interest defence would allow room for what the Sun did here.
Brian’s point that even with a public interest defence, there will be a discincentive to launch such operations, since they may need to be successful to avoid penalties is valid. But could such a law be drafted to allow a public interest defence to launching the surveillance per se? I guess it may be difficult without nullifying the intent of a privacy law.
I work on the principle that a man’s home is his castle.
Can’t see anything wrong with photographing people in public, but homes should be sacrosant, even for this unpleasant character.