Follow the laws and it isn't an issue. I'm pretty sure banning someone for that stuff is probably illegal, too.
For example, in the UK we have a very famous case (The Consulting Association (TCA)) where building contractors joined together to build a list of construction workers they didn't want to hire - this was determined as a criminal breach of UK data protection law.
So have at it, I love a challenge...
I don't think you should be doing business anywhere if customers being familiar with the law and knowing their rights scares you. Frankly if you are running a business, you should be familiar with the laws and regulations, doing otherwise - especially when someone points out that your behaviour is illegal - is negligence and punishment with a fine is completely appropriate. Welcome to living in a society.