An independent security researcher claims he was threatened by Facebook after he responsibly revealed a series of security vulnerabilities and configuration flaws that allowed him to successfully gained access to sensitive data stored on Instagram servers. Instead of paying him a reward, Facebook has threatened to sue the researcher of intentionally withholding flaws and information from its team. But, remember, even responsibly reporting a security vulnerability could end up in taking legal actions against you. Facebook said he “did not threaten legal action, nor did [he] ask for [weinberg] to be fired”
Source: https://thehackernews.com/2015/12/how-to-hack-instagram.html