With the thumb out, it means "I Love You" in sign language. When the thumb is covering the two middle fingers that are against the palm, THAT is the sign of the devil because it forms the goat. The "rock and roll" version of this is with the thumb covering the two middle fingers.
I love you in sign language (take note of the bottom picture too) :
You are not allowed to view links.
Register or
LoginSign of the devil :
You are not allowed to view links.
Register or
LoginA lot of people confuse the two because they are similar.