Fair use is a "very gray area"

Fair use is a "very gray area," says Julie Ahrens, who runs the Fair Use Project at Stanford University's Center for Internet and Society.

"There are lots of things that are not clear."

"I get things where people are like, 'Are you sure I can do this?' And the best I can say is, 'Yes, you should be able to,' " she says.

Famed quotation isn't dead -- and could even prove costly