The scary alert from site stop.policeguard-alertpatrol.com is a fake FBI warning which may appear in your browser today. You must be very careful when you see it, because this is a scam! Hackers have invented the way of hijacking many browsers with this fake FBI warning that claims this – Your browser has been locked. This is a virus infection which these days is very active not only in the US but in many other parts of the world. It is categorized by many legitimate antivirus programs as Trojan:HTML/Browlock infection.