Sentry - Disable user registration
The official sentry docker image allows user registration per default. This allows access to logs containing confidential information.
How I found your sentry instance and how to disable user registration
Update 24/6/17 12:50Z: Pull request started in getsentry/sentry mentioning an issue by @alexandervlpl:
last night thousands of people received letters from a script that checked the availability of ALL data on their Sentry servers, because they forgot to turn off the registration, or did not know that it was turned on by default at all