Crowdsourced curation is largely effective, and sponsors mostly know it's permanent (there is a partial refund policy, but it's designed to punish abuse).
We also have an abuse-report page in our Discord and we have a vote stream at https://content.hivesbi.com that shows all the Hive SBI voted content and the value of Hive SBI votes so that it's easy for even non-technical users to review our votes and report potential abuse (or decide who deserves even more support).
RE: Hive L2 - return of the bidbots