There is no law that says standard Do Not Duplicate blanks are illegal to copy. Most places that cut blanks will simply refuse to copy them, whether it is because they don’t want to do anything wrong, or because they think they don’t have the correct blank in stock. Typically locksmiths will try to determine whether they are doing the right thing by copying a DND blank. We just want to feel comfortable that we aren’t giving someone access to something they shouldn’t have. Bottom line… be prepared to have some form of proof that you have a legitimate reason to get a copy.