how it would work:

typing a username in the search bar in the s/a would either:

reveal any previous scams made by that user,
or reveal any scams performed on that user.

if it is the former, well, the trader searching the name probably wouldn't trade with that person, or it perhaps would give legit higher ground in the argument of who gives first when trading.
if it is the latter, then at least theres some other usernames to look out for in the future.

there are many unlocked scammers out there, and the people in the s/a forum are more often than not rubbish (took me like half a year to get someone locked); by using the search bar, we can make better decisions on who's trustworthy, or not.

Na, would also bring up false accusations as well.

This has been rejected before

people should at least read the accusations that the person's involved in though, and decide for themselves whether its a genuine accusation or a false one