It is resistant to that sort of manipulation. The algorithm looks at users' voting history to see how often their voting is accurate and vice versa (i.e. if the

It is resistant to that sort of manipulation. The algorithm looks at users' voting history to see how often their voting is accurate and vice versa (i.e. if they vote something is helpful, does or tend to ultimately get marked as helpful?). The algorithm also looks at how one-sided a note is. The more a note is voted helpful by those who've disagreed in the past, the more likely it will have the helpful status.