Not that I have been looking for security issues or anything. I am just curious if they have a policy regarding people searching for and reporting potential security issues?
There is no specific 'bounty', no.
That being said, if you post a good bug report here, you'll tend to get lots of Unicorn Points (otherwise known as Meta Reputation) for your question reporting it.
One extra thing to mention, with thanks to Jeremy (is he still on vacation?): If an exploit you find is something that could be dangerous to post publicly, you should report it privately via the Contact link on the site. This would be something that could be used destructively to the system itself, as opposed to just minor functionality hacks.
Also, you mention actively looking for vulnerabilities. The standard warning for 3rd party folks doing that would apply: Don't poke so hard that it's easy to mistake you for trying to exploit, rather than just looking for them. On the good side, though; Stack Exchange is not like some companies which can tend to react badly to legitimate reports of vulnerabilities. If you report responsibly and with honest intentions, they will react well.