I originally saw this at WB so I thought I would pass it along.
For now a temporary ban has been place on these clients as news from some of the users with security issues including the MPAA and RIAA. They are the most stable but issues with security is more important for the users, and the site. You guys got till friday to switch after that we will kill the rights to those that still decided to use it.
The versions will include 1.7, 1.71 and all betas, and any new utorrent
Its best to stick with 1.6 and 1.61 for now till the issue is resolved. Older utorrent before 1.6 is not suggested also, as those we also plan to ban
This was decided for your safety and ours.
link to utorrent 1.6 and 1.6.1
I have read a little more elsewhere at utorrent.com in the forums where they discuss the new versions and the "extra" data being sent out.
You can check that HERE
For your own piece of mind, I would recommend checking your other trackers for any issues.