Privacy and Punishment

Henry Porter has a blog post at the Guardian where he argues that it is scandalous that Members of Parliament will go unpunished for their abuse of the expenses system while ordinary citizens are punished disproportionately for minor offences. He lists as examples the electronic tagging of a woman in Ellesmere Port for abandoning a kitten for two days (with a £2440 fine thrown in for good measure) and the announcement of a police chief that all acts of littering will be punished with a 24 hour jail sentence.

Porter's piece isn't explicitly about surveillance, but I'm wondering if there's an interesting sort of privacy intrusion that can be identified here beyond that usually discussed.

Just about everyone agrees that punishing someone unjustly is always wrong. And most people agree that intrusive invasions of privacy are at least prima facie wrong (even if they think that some other value outweighs the wrong in the particular instance). Is there something additionally wrong when a person's privacy is invaded and they are then punished for some aspect of their private conduct? Is an invasion of privacy by an agent who might unjustly punish you on the basis of the information they find not only more unjust but actually more invasive?