Some adware programs have been criticized for occasionally including code that tracks a user's personal information and passes it on to third parties, without the user's authorization or knowledge. This practice has been dubbed spyware and has prompted an outcry from computer security and privacy advocates, including the [Electronic Privacy Information Center]? (http://www.epic.org/). This feature is not, however, an essential feature of adware per se; that is, one can easily design an adware program that does not track a user's personal information.
A number of software applications are available to help computer users search for and modify adware programs to block the presentation of advertisements and to remove spyware modules.