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.

EFF says that Barlow, "always saw the internet as a fundamental place of freedom, where voices long silenced can find an audience and people can connect with others regardless of physical distance."

He also wrote lyrics for Grateful Dead songs including "Black Throated Wind" and "Blow Away," among others. He also co-wrote "Cassidy" with Grateful Dead founding member Bob Weir.