Nothing wrong with that. It's routine practice in the direct mail advertising business for firms or brokers to buy, rent and sell lists of donors or other specified groups. A conservative from Texas, Richard Viguerie, developed the practice in the 1960s and was the first to computerize lists of political donors. It helped get Ronald Reagan elected not many years later.
You might not have a problem with them selling the list of names. IMO I think it was a lousy thing to do.