Wyoming native John Perry Barlow, an internet activist and former lyricist for the Grateful Dead, has died.

The digital-rights group Electronic Frontier Foundation said in a statement that Barlow died early Wednesday morning in his sleep at age 70. The cause of death was not immediately known.

Barlow, who grew up on a ranch near Pinedale, Wyoming, co-founded the EFF in 1990 to champion free expression and privacy online.