Click fraud is part of the cost of advertising but there are ways to deal with a lot of it. It takes some work. There are several articles on the subject if you search Google using the link below:
I found this two very interesting articles with this search but there are many more:
The best advice I can give you is to monitor for it regularly, make adjustments when you see it and don`t use a PPC service without checking them out first.
If you get out totally, you may not be see at all...