[ Thanks to E.
Stride for this link. ]
“Firekeeper integrates with the Firefox browser and
monitors your browsing. It intervenes if it detects malicious
traffic. Firekeeper’s detection engine is modelled on the popular
open source intrusion detection system (IDS), Snort. Snort uses a
series of rules that define the characteristics of malicious
traffic, such as what protocol, ports and payload it uses. These
rules often use regular expressions to detect malicious
attacks.”