For such a little group, they sure cause more than their fair share of trouble. They wake people up and disrupt their work and leisure activity with a message that is pure crap. Their arguments are so specious that people can and do fall for it, and then it's almost impossible to leave once you are in. They want people to get whole families in, so if one leaves or cannot follow all the rules, they will have major consequences.
I would like to see that tiny group abolished. Not by laws, since they will just go underground and do their work anyways. But, if they can be embarrassed by public relations campaigns, then at least people will not be going in. True, those already in will be told to not believe the "lies" that the government puts out about the organization. But, that campaign has already worked for things like smoking (there are fewer people starting smoking now than was the case in the 1960s). All they have to do is a media blitz portraying Jehovah's Witlesses as being totally uncool and unsexy, and the doctrine crap, and people will be all the more inclined to stay away from the cult. Links to viable apostate Web sites that expose the cult's dirty secrets will enhance the program all the more.
Do that, and the group will stay tiny. They will waste their gas going from door to door, but no one will want any part of them. They will lose what little significance they already have when everyone slams their doors in their faces or exposes them to apostate literature. Then they might dwindle even more for apathy.