Website analytics firm KISSmetrics and more than 20 of its customers, including Spotify, AOL’s About.me, Slideshare.net, Spokeo and the news site Gigaom.com were sued Monday on the grounds that KISSmetrics’ tracking technology violated federal and state privacy laws.

The suit (.pdf), filed in a federal court in Northern California, is seeking class-action status and unspecified damages.

At issue are methods KISSmetrics used — first reported by Wired.com — to track users who have deleted their cookies. The company juggled a variety of other technologies including Flash, Silverlight, HTML5 and so-...