This issue has come up from time to time. You can apply Preferencing. ie: Tools>Options>Advanced>Preferencing & set the minimum no. of files these people must share for them to upld from you. I don't think the browse is a good way to determine whether they're sharing or not! To help to browse somebody they need to have Chat enabled & even then there's no guarantee you can browse them. There's many factors at play here. The LimeWire 4.1.x (666) build does have the possibility of filtering out certain clients. As I found out here But that's a variation on the official LW release.