There's also the issue of "what constitutes infringement?"
I suppose if someone is intentionally seeding a bunch of stuff to some network and writing the .nfo files that go alongside, that could possibly be argued to be criminal infringement (since their copyright abuse would be against many many claimants).
But what of someone hosting an analysis of a song? Part of a song? Using the preview clips off iTunes as a backing track to a home video? Hosting a song they wrote and recorded themselves on their own website, where they sold distribution rights for a different recording to some studio? The problem here is that interpretation of copyright law doesn't just vary from country to country, but from court to court, and you can even have different rulings from the same judge in the same court, due to the fact that copyright is a social contract codified loosely in civil and federal law.
That said, I think the gist of what the MP said was a good idea; the ability to jail someone for widespread commercial infringement of copyright for profit with no remorse after being warned might merit jail time. But at this point, it's not really the copyright infringement that merits the jail time. Plus, we're entering slippery slope territory here: if they do it for the really bad cases, that leads to lobby groups pushing for it to be applied to "pretty bad" cases due to the effectiveness of doing it for the really bad cases, and so the trip to the splashdown begins.
If we could guarantee a lack of corruption and lazy thinking (letting lobbyists and others do the work for you) in government, this would make sense; otherwise, it needs a social solution for a social issue. Save the courts for issues that directly deprive citizens of their rights. And no, a corporation is not a citizen, and getting paid multiple times for creating something is not a right (that's a contractual issue).