It's not just the blues riffs. They took lyrics as well. They have been sued more than once, but all was settled out of court. "You Need Love" by Willie Dixon is one (for Whole Lotta Love). "Babe, I'm Gonna Leave You" (a folk song by Anne Bredon) was another settled out of court. "Dazed & Confused" was by Jake Holmes. He opened for the Yardbirds and that's where Page was made aware of the song. Don't know what was determined with that one. The intro to Stairway to Heaven is from an instrumental called "Taurus" by Spirit. Zep used to see them perform. Randy California was aware of it but never cared to take legal action. I dug Zep's takes on these songs, i'm justing stating the facts that i have known for some time.
