In its early days, the Internet was more Wild Wild West than World Wide Web. It was a new and insecure frontier full of pseudonyms and scammers eager to take advantage of unsuspecting early adopters.

Not much has changed on that front, though there are sheriffs to police things now (sometimes a little too much). Still, bugs creep in, and top tech firms would much prefer that skilled engineers find these vulnerabilities instead of hackers with criminal intent. Enter the bug bounty hunters.

Like real bounty hunting, bug bounty hunting can quickly bring in lots of cash, but it also involves a lot of risk for the reward. Companies may want to squash news of vulnerabilities in their systems and seek to punish those who find them. Or they may decide to shower them with money in thanks. Rewards can reach into six digits, if self-reporting is to be believed. Google alone last year paid researchers more than $2 million.

Platforms like Bugcrowd and HackerOne act as wanted posters for the Internet. Most major tech companies, from Google and Facebook to Microsoft and Apple, offer bug bounties. But there are a few entities you might not suspect are looking for cyber-security help. Check them out in the slideshow.