filter_ratings_by_ip turned on in site controls
I turned them on today.
Reason: People now can register under multiple user names and duplicate vote their own comments ratings, etc.
This variable determines whether or not multiple ratings from the same client IP address are counted when determining a comment’s score and a user’s mojo. The possible values are: 0) allow any number of ratings from one IP; and 1) only count the first rating from any given IP address. The default value is 0.
Before turning this variable on, consider that there are several situations in which multiple ratings may appear to come from the same IP. One is the case of a lot of computers behind a firewall; all of the computers will appear to come from one IP even though there are many people and many computers. Another is the case of a computer lab, where many users may log on or off of any number of computers at different times, and two different users may rate the same comment from the same computer. This variable does not affect the normal behaviour of only allowing one rating per account.