Isn't the most interesting part of the story missing, here? A co-op doesn't magically suppress all problems and abuse. It sets up a context where they can be

Isn't the most interesting part of the story missing, here? A co-op doesn't magically suppress all problems and abuse. It sets up a context where they can be dealt with without any "big thingie" (in most cases some government body). Therefore what did you do after discovering the abuse, and what were the effects? More generally anyone paying for Internet access should receive some explanation about why the gateway/router/hotspot/wotever password must be kept secret. When someone abuses (be it a neighbor or a member of the co-op) you brief everyone authorized to access ("NEVER give the password") then change the password, hardening it if you suspect that it was discovered by bruteforcing. If the freerider is in the co-op you may first explain the situation to him, then ask him to either pay his future share, or abstain from using this service. If you are unhappy with his reaction you may talk about it to the other members of the co-op when briefing them, maybe with a proposal (to give the boot to the free rider, to have everyone lesson him...) and ask for other proposals. This situation (freeloader in the co-op) seems better to me than the classic one, where the freeloader is a neighbor. Confronting a neighbor may lead to unpleasant experiences (you first have to discover which neighbor is the culprit, he may try to deny or to punch you, or ack whatever you say then abuse again...).