I searched google help for how to block a website from google results. ALL complaints were because of experts exchange. I don't know if anyone voluntarily goes to EX. SO I go to regularly. Check for how many requests a single user does to EX. Basically a person might go to EX's 3 or 4 pages in a day by accident then never again if possible. A unique ip is not a good factor.
Not voluntarily, but would I be out of place saying that I've actually used some of the information on the EX hits, and they have helped me? That's not to say I didn't wish the answers were on StackOverflow instead though.
My friend was paying EE for their service and moderately happy with it until I showed him how they display the answers publicly after the scroll barrier of google originated requests (and not others). His response was something along the lines of "why those little..." He promptly cancelled his subscription with them.