i think - from how the article reads - they are going to go after the high uploaders
High upload ratio means nothing, it's just a number in a database which doesn't prove a thing. It's incredibly easy to fake upload on any bit torrent tracker, you can instantly increase your upload amount on any tracker by sending a single command to the tracker . You can also download one of the open source clients and change a single line of code so the client sends incorrect amounts of uploaded data back to the tracker (and hacked clients are available for download). Many people DO cheat their upload amounts/ratios on these kind of trackers (the ratio trackers based on the old torrentbits site).
If any of these cases reached court based purely on somebody's upload/download ratio any halfwit with a laptop, a packet sniffer and a telnet client can prove to the court that the upload figure in the database is completely unreliable and can be changed in under a minute. You could have a 900gb upload figure and not have uploaded a single byte. None of this information is a secret btw, search for bit torrent ratio spoofing. It's was once headline news on most of the big tech sites such as digg and slashdot so I think it's fair to say that millions of people know about this.
Having said that, it's a different story if you were the original seed on a torrent (responsible for uploading the original file and torrent). That's much easier to prove because the file can't have become seeded by anybody else if you were faking the upload. This still doesn't prove absolute guilt though, there's any number of defences against it (trojans, unsecured wireless, etc). The cost, time and complexity of tracing thousands of people based purely on IP address's, all based in different countries with different laws, makes it unlikely they'd go after anybody except maybe the top few uploaders (if anybody at all) imho.
I've been following this story in the reg, does anyone know what the guy has actually been charged with (if anything) as they seemed to be using trumped up fraud charges of some sort that sound like they will never stick.
"the police said that they had made the arrest on suspicion of conspiracy to defraud and copyright infringement."
It will be interesting to see where they go with that because I was under the impression that copyright infringement was a civil offence and therefore not a matter for the police. Still, torrent files contain no copyright material, it's just a text file and at present we have no law against facilitation of copyright infringement. I've no idea how the conspiracy to defraud works either, the only thing I can think of is conspiracy to defraud the sites users?