"I wasn't trying to hack your server, so why was I blocked?"
There are certain things like getting your password incorrect too many times within a certain period of time, when trying to log into a service that will trigger the firewall to block you.
This is not an indication of guilt, but can be done by accident.
Due to security reasons, we cannot tell you what triggers there are, and how they are set off. In normal use, this should not be an issue.