The Comodo Certificate Authority had been compromised via one of its small regional resellers and tricked into issuing fraudulent certificates for a variety of high-profile websites such as Google. Sony was forced to shut down the PSN entirely for several weeks until it could be brought back online in a secure manner. The cost of an attack may be far in excess of the business value of the data itself. The security of every browser user in the world really does depend on every little CA reseller and sub-CA that we’ve never heard of before.”]
Source: https://www.csoonline.com/article/2130526/top-security-incidents-of-2011.html