I don't think 'pirating' TV Episodes is that big of a deal. I mean the site the mentioned, I know a few people who use it and if you think about it your watching it at a lot lower res and on a computer screen so by usng that they anit getting much over. (by the way I know it's possible to get hold of much better rips but that's not what I'm talking about here)
Plus if you look at shows like 24, Prison Break they usually get aired anyway on FTA channels, like Five. So no one really loses money or anything and most people I know pay TV liecene regardless of this. Plus you get the advantage of watching it hours after U.S. airtimes which is usally more than a week early here and to some people that means a lot but I guess that's one reason for the arrest.
It is also TV on demand so you wont have to miss anything or record it on VCR, which they also used to moan about also which in theory really does nothing to harm the industy not everyone has an eased schedule.
I think arresting someone is alittle extreme and I'm sure they will go after a lot of recorded IPs/accounts too.