Blocked URLs refer to the Destination URLs used by Advertisers. If an Ad uses a Destination URL that has been blocked in the system, that ad will not be shown, and will simply be exempted from further presentation until the destination URL is updated to be a valid, unblocked URL.
This feature enables Brokers and system management to create a list of URLs which may offend some users, or to more closely manage the URLs available to users for a variety of reasons, such as a security measure for a website known to be fraudulent.
The implementation is applied 'retrospectively' such that any new URL added to the Blocked URL list will apply to all ads in the system from then on, blocking any ads that use that now-blocked URL as the destination URL.
Blocked URLs are system wide, so all Destination URLs within a broker's installation are affected by the blocked URLs specified in the Blocked URLs function.