A company is maketing a product called Lover Spy, which allows the customer to send a “greeting” to an acquaintance. That greeting contains a hidden application that installs itself on the victim’s computer and reports back information on that person’s online activities. It’s intended to be a way for jealous lovers to keep tabs on their partner. It’s a remote version of the old “install a keystroke logger on your boyfriend” trick. It’s also probably illegal in the United States.