Phorm is a digital technology company known for its advertising software system Webwise, a service that monitors browsing habits and serves relevant advertisements to the user.
The Webwise system works by using HTTP cookies to store user settings. It then sets unique PHORM tracking identifier (UID) for the user. It stores a tracking cookie for each website the user visits on their PC each of which contains an identical copy of the users UID.
PHORM says that the collected data would be anonymous and that they would never be aware of the users identity or what they have browsed and that their system even offers some protection from phishing and online fraud.
Reaction to PHORM's service has raised concern in regard to privacy and property rights in data. Most computer security companies would recognise it as adware.
A security researcher from Cambridge University has said that the users UID cannot be prevented from being sent to webisites using https allowing websites to associate any details collected about the user with the UID.
Questions about the legality of PHORM's service have been raised by organizations like the Open Rights Group (ORG) saying that both parties need to consent to interception for it to be lawful.
In 2008. the United Kingdom Information Commissioner's Office said that the service would only be legal as an opt-in, not opt-out service.