For anyone familiar with the Counter-Strike competitive scene, you know about ESEA. They just recently launched a bounty program that puts their website, game client, and game servers in scope for security research.
I spent a night taking a look over the website and found a few vulnerabilities. The most interesting discovery was a Server-Side Request Forgery vulnerability. Using a cool trick that Ben Sadeghipour (@NahamSec) showed me, I was able to pull private information from ESEA's AWS metadata.