Cloudflare, a company that provides internet security services for so so much of the internet, just fixed a bug that effected their services. While it's incredibly unlikely that anyone here was compromised, it's a possibility, so when you get a chance please change your password! Lots of the internet uses Cloudflare, so it would be good security practices to change your passwords on those sites.
If you haven't already, look into using a password manager like LastPass or 1Password.
More details follow:
From a list of possible effected sites:
Between 2016-09-22 - 2017-02-18 passwords, private messages, API keys, and other sensitive data were leaked by Cloudflare to random requesters. Data was cached by search engines, and may have been collected by random adversaries over the past few months.
This appears to be fairly rare, according to the company:
The greatest period of impact was from February 13 and February 18 with around 1 in every 3,300,000 HTTP requests through Cloudflare potentially resulting in memory leakage (that’s about 0.00003% of requests).
I don't believe that the services we match up with the ones Cloudflare says were leaking data, so this notice is really about being as cautious as possible. Look out for simular notices on other sites you use, and stay save friends!