This is a bad idea.
Minor exploits might be ok to play with, but once all the easy stuff is found, what happens when users are playing with the site in such a way as to harm the experience of other users?
Who gets to wade through all the "lol, I used a userscript to change the logo, gimme the hacker badge" and "Hey, I found that if I send thousands of requests a second the server stops responding, gimme a hacker badge" messages?
This is not behavior we should be encouraging. The awesome software and network engineers at Stack Exchange are sufficient to the task, and we shouldn't encourage another thousand or million people to perform random attacks on the site in the hopes of exposing a weakness.