Through its PestPatrol research, CA found that Kazaa posed a greater threat than other programs in its top five spyware list because of its widespread popularity. Kazaa claims that its software has been downloaded 214 million times.
CA gave Kazaa a high "clot factor," its measure of how much a program slows a machine by adding unnecessary registry entries and directories. However, classifying a popular application like Kazaa as spyware is a delicate matter, and CA admits this creates difficulties in attaching labels.
More information at Cnet
CA: "Kazaa is the biggest spyware threat"
