Vigilantiism can be categorized as:
- trivial sysop vigilantiism, e.g. to block IP of trolls they do not like, temporarily preventing them from improving the GFDL corpus or etc.
- more serious developer vigilantiism, e.g. release of vandalbots that are used in denial of service attacks to harass political and legal opponents off the web entirely, censoring them, or to keep IP range blocks in place that sysops can't undo
- deadly serious results of direct conflicts between different claimed sources of authority and legitimacy for actions in the real world