How does Facebook disable the browser's integrated Developer Tools?

So apparently because of the recent scams, the developer tools is exploited by people to post spam and even used to "hack" accounts. Facebook has blocked the developer tools, and I can't even use the console.

How did they do that?? One Stack Overflow post claimed that it is not possible, but Facebook has proven them wrong.

Just go to Facebook and open up the developer tools, type one character into the console, and this warning pops up. No matter what you put in, it will not get executed.

How is this possible?

They even blocked auto-complete in the console: