The use of GPS tracking devices without obtaining a warrant is an area of law that has not yet been addressed by the legislature.
Click on the post for an interesting article in the Janesville Gazette.
The Evansville Observer Archive: The unofficial history of Evansville, Wisconsin from 2005-2013: Thousands of Video and Audio and Articles; Free: To Search scroll to the Search this Blog line and enter name of person, topic, or issue. Then scroll up to see all articles. Or use Google Search by topic. Enjoy.