hm ... firstly i think leeching in the meaning of finding a good server, browsing its web-page and getting all the stuff you were looking for anyway from it is ok. i assume you are talking about what is often called "freeloading", i.e. downloading without sharing ...

it ****** me off to have uploads running with >400kb all the time and my downloads won't get above 100kb. also my statistic usually tells about 100% success for uploads and won't get above 30% for downloads. this surely means that the people having a good connection to me (thus i would have a good connection to them) don't share their files. but i keep up the hope they will in the future. might always be the case that one hasn't got files to share (yet) or just doesn't share that kind of files i am looking for. therefore cutting them off really wouldn't help

so keep up the hope. the people who are starting to cut downloads because they _think_ there are non-sharing people at the other end certainly do not make things better.