A machine-executable method implementable in a system operable to execute a browser application having at least one security-context zone and operable to apply at least one security policy to interaction between the system and web sites corresponding to domain identifiers populating the at least one security-context zone includes comparing a first set of domain identifiers populating a first security-context zone of the at least one security-context zone with a second set of domain identifiers. The method further includes populating the first security-context zone with at least one second-set identifier not included in the first set of domain identifiers.