It can depend on what signature campaign you are in. Some cannot afford to have people use 2 or more accounts

and will be on the lookout for people with two accounts. If you are caught, you will most likely be kicked from the

campaign. If you want to take the risk, I suggest creating seperate bitcoin addresses for each account, this way it will

be very difficult for the signature campaign to tell that you are the same person. However, I don't recommend it.