Proposal collateral

To prevent abuse and spam users creating a proposal could be asked to provide collateral. This concept exists on Cosmos for instance.

The collateral would begin at a fixed nominal amount, e.g. 10 SOL, and increase with every active non-resolved proposal that exists, thus creating a disincentive to spam new proposals before older ones are voted upon.

The proposer would receive back their full collateral regardless of whether the proposal passes or fails, except where the plurality has voted for "No with veto", this is a dissenting vote that further wants to slash the collateral of the proposer, to be used for proposals that are extremely bad, harmful or time-wasting.