I've come across a situation where I was purchasing leads from a particular source. Unfortunately, it turns out that the leads may not indeed be legitimate. I don't know the exact situation, but it probably has to do with IP addresses, modifying them, and other technicalities of which I am unfamiliar with. Though generating these "fake" leads and earning money is definitely against certain companies (that pay you for generating the leads) terms of service, am I at any legal fault for the traffic that I brought to my site, even though it wasn't legitimate?
If you hired the service, you are legally responsible if the traffic violates an advertisers TOS. Google is especially sensitive to the lost cost bulk paid traffic services.
I understand, but other than getting kicked off of the program, are there any legal ramifications that I may encounter?
Well, there could always file a civil lawsuit to recover any money they had paid you, but I don't think this is likely unless you are talking about a substantial amount of money. If you were somehow participating in a scheme to defraud the company, you could face criminal charges - but this would depend on exactly what was done, and did you know or should you have known, what was taking place.