From now new deactivation system for members is implemented.
What does it mean?
Toplist Member can be deactivated manually by himself, by TopList manager, by admin or automatically (for example if bad content is detected automatically or site permanently returns 404).

After deactivation you can see who deactivated member, deactivation reason, deactivation time, deactivation comment.

If a member is deactivated by admin or automatically then only admin can activate him again.
If a member is deactivated by TopList manager then only admin and manager can activate him.
If a member is deactivated by member himself then admin, manager and member can activate him.

To get deactivation form you should click on "Status: active" link in member's settings form in your control panel. The deactivated member will disappear from the toplist after next rerank (automatic or manual).