An entire industry has built up around combating spyware, and there are many programs designed to remove spyware, to prevent its installation, and to detect and remove it from email. A number of companies have incorporated forms of spyware into their software, primarily for purposes of advertising. While these types of programs are not considered to be malware, they are still spyware in the sense of watching and observing with advertising in mind, making them a cross between spyware and adware. However such applications are still spying (hence spyware) and advertising (hence adware). It is somewhat arguable whether such ‘legitimate‘ uses of adware/spyware are malware, since the user often has no control over whether these ‘legitimate‘ programs are installed on their computers, are generally unaware that these programs are infringing on their privacy, and in any case these programs still use the computing resources of the host‘s computer without permission