This tech support scam page asks for a ‘safe key’ to unlock your browser. Using the X button at the top right corner or clicking on Cancel multiple times does not close the browser. The only difference is the fact that their are very few instructions, other than a phone number to get your safe key. Using the TaskManager to kill the browsers running process may very well end up calling for assistance except theyd be calling the scammers themselves!”]
Source: https://blog.malwarebytes.com/threat-analysis/2015/10/tech-support-scam-asks-for-passkey/