I suggest that we delete all untagged players after several days of being untagged. All players would have to join an established clan. We could implement a clan registration system that qualifies people with some reputation for fair play to start a clan or be responsible for leading one.

Clans already have rules and policies in place to deal with suiciders from their ranks. This would bring the management of "suiciders" down the the clan level. And it would eliminate the untagged suiciders.