I have been using Huitter.com for bulk unfollowing tweeps but now it does not seem to work for me as I cross 35,000 followers. Twitter Karma too doesn't work here for me. The only option left for me is is to use buzzom.com and tweepi.com. However, the problem here is that I can unfollow only 25-50 people in one go using these. I need to unfollow over 4000 people who are not following me and doing it using buzzom or tweepi, will make it a tedious task for me. Can you suggest me some tool that can do this task of bulk unfollowing easily?