Mousetrapping

Mousetrapping is a technique used by some websites (often tech support scam sites) to keep visitors from leaving their website, either by launching an endless series of pop-up ads, redirects or by re-launching their website in a window that cannot be easily closed (sometimes this window runs like a stand-alone application, and the taskbar and the browser's menu become inaccessible). Many websites that do this also employ browser hijackers to reset the user's default homepage.
One way to end the cycle may be to use keyboard shortcuts (like Alt+F4 in Windows) instead of the mouse to close the windows. Multiple windows can be closed quickly with this method, although it may not always work if there is a resident program which is opening them. Browser extensions which disable scripting for all but a trusted whitelist of sites, such as NoScript Security Suite, can be a useful defence against mousetrapping and malicious sites.
The Federal Trade Commission has brought suits against mousetrappers, charging that the practice is a deceptive and unfair competitive practice, in violation of section 5 of the FTC Act. Typically, mousetrappers register URLs with misspelled names of celebrities (e.g. "BrittnaySpears.com") or companies (e.g. "BettyCroker.com" and "WallStreetJournel.com"). Thus, if someone seeking the "Betty_Crocker" Website typed "Betty_Croker", the person would become ensnared in the mousetrapper's system. Once the viewer is at the site, a Javascript or a click induced by promises of free samples redirects the viewer to a URL and regular site of the mousetrapper's client-advertiser, who (the FTC said in the Zuccarini case) pays him 10 to 25 cents for capturing and redirecting each potential customer. An FTC press release explaining why it opposes mousetrapping states:
Schemes that capture consumers and hold them at sites against their will while exposing Internet users, including children, to solicitations for gambling, psychics, lotteries, and pornography must be stopped.
Some major, well-known U.S. corporations have used mousetrapping to keep viewers on their web pages.