Del Taco is offering a coupon for a free Crispy Chicken Taco right now to Facebook likers.
You can choose from Bacon Ranch or Creamy Chiptole. You have to allow them access and all that in order to get the coupon.
You can find a Del Taco location near you here. I would call and confirm your location is accepting this coupon before you go to a lot of trouble. Sometimes with fast food franchises they will refuse to honor these types of coupons, even though it is posted right on the web site.
Just to clarify, it is free with a purchase, not just free.