this is what is said about this rule in an Access Protection technote:
Some viruses look through the Internet Explorer cache for email addresses and website passwords. This rule prevents access to anything in the Internet Explorer cache except by Internet Explorer.
Any process that uses the WinInet library or hosts an Internet Explorer control in a window (*)can access the cache; therefore, you may need to add process to this rule if it is enabled."
*Obviously if this is not true for your organization then you could disable the rule.