The United States of America has taken many steps to stop the installation of Spyware on home computers...

Legal Situations in the United States
The United States of America has taken many steps to stop the installation of Spyware on home computers, the Computer Fraud and Abuse Act (CFAA) covers unauthorized installations. Also, there are different laws that include false advertising, deceptive business practices, and trespass, which fall under Spyware in some ways, this could come under the Trade Descriptions Act for misleading the consumers.

Lawsuits in the United States
In the past year, there has be many lawsuits concerning Spyware such as the Attorney General's case. Eliot Spitzer sued a major Internet company claiming the marketer installed Adware and Spyware that brought up useless pop-up advertisements to slow and crash personal computers. After a full investigation, Spitzer inferred that the marketer installed a wide range of advertising software on different personal computers across the nation. Some Internet corporations also have filed lawsuits saying that the website owners did not refer to their programs as Spyware.

Different Consequences of Spyware
Recently, the United States has found out that Windows-based computers, whether used by adults or children; can rapidly accumulate different kinds of Spyware in no time. The biggest consequences of Spyware would generally include a loss of system performance (mostly over fifty percent) and horrible stability issues, such as hangs or crashes. In some cases, it makes it hard to connect to the Internet. Since 2004, Spyware infection causes more visits to professional computer repairers than any other single cause.

Most of these cases, the user had no awareness of Spyware and originally thought it was a virus eating at his/her computer. Some Spyware products have additional consequences, such as stealth dialers. Stealth dialers attempt to connect directly to your telephone number, instead of the your ISP. This means, that when you connect to the Internet it will cost three times more on your telephone bill. This is not just invasion of the consumers privacy but its also tresspassing on the consumers computer because they did not give consent for the applications to be on there or had no prior warning.

Resources:
http://en.wikipedia.org/wiki/Spyware#Legal_situation_in_the_United_States_of_America