On: Invert, always, invert

[fendy3002]

Then in reality the website is down due to the simplest things that's so common we don't reconsider it, such as user input some special characters that makes the server error.

Edit: I'm not downplaying the importance of prevention

[cutemonster → fendy3002]

> server error

Seems to me that bugs is then a high risk in that project. And to prevent or reduce the number of failures, the project needs an auto test suite