Google Analytic Spam Bot

[Skillz]

I keep seeing a bunch of fake referrals on my analytic's from a bunch of different sites. Does anyone have any information on this? I am curious to see how they are doing it. I'm sure with all the fake referrals they are giving out, they get a pretty high flow of traffic. Does google penalize you for doing this? Sites like SEmalt are one of the top one's I have seen. I figure if you use this method, you cannot really use adsense to monetize, could you?

Anyway, if anyone has any insight on this let me know. I am sure you could probably build a pretty profitable short term business with this method. But sustainability is probably short as soon as google figures out how to fix these fake referral sites.