Document use of params for sound proof generation, with counter-examples.

[jzaki]

In hackathons there are often submissions that generate proofs, but can be misused to either prove different things or not uniquely prove what their solution proposes. Allowing a bad actor to either affect other users, or just advantage themselves.

[critesjosh]

It would be good to list specific examples anti-patterns, perhaps with links to projects.

Some that come to mind:

• passing proofs on chain that don't have replay protection
• voting applications that don't protect against replay attacks
• user supplied public inputs that are not checked or enforced. Eg a user can provide false inputs. Should be passed by a contract where possible