http://www-users.cs.umn.edu/~lam/papers/lam_group2010_wikipedia-group-decisi... :
"We also found that there have been two bots (computer programs that edit Wikipedia)—BJBot and Jayden54Bot—that automatically automatically notified article editors about AfD discussions and recruited them to participate per the established policy. These bots performed AfD notifications for several months, and offer us an opportunity to study the effect of recruitment that is purely policy driven. We use a process like one described above to detect successful instances of bot-initiated recruitment: if a recruitment bot edited a user’s talk page, and that user !voted in an AfD within two days, then we consider that user to have been recruited by the bot. Using the above processes, we identified 8,464 instances of successful recruiting. Table 2 shows a summary of who did the recruiting, and how their recruits !voted. We see large differences in !voting behavior, which suggests that there is bias in who people choose to recruit. (From these data we cannot tell whether the bias is an intentional effort to influence consensus, or the result of social network homophily [14].) Participants recruited by keep !voters were about four times less likely to support deletion as those recruited by delete !voters. The participants that bots recruited also appear unlikely to support deletion, which reflects the policy bias we observed earlier."