<< Before the 2006 Michigan gubernatorial primary, three political scientists isolated a group of voters and mailed them copies of their voting histories, listing the elections in which they participated and those they missed. Included were their neighbors' voting histories, too, along with a warning: after the polls closed, everyone would get an updated set.

<< After the primary, the academics examined the voter rolls and were startled by the potency of peer pressure as a motivational tool. The mailer was 10 times better at turning nonvoters into voters than the typical piece of pre-election mail whose effectiveness has ever been measured. >>

Source:
http://www.nytimes.com/2010/10/31/magazine/31politics-t.html

I hope that doesn't become a common practice. I realize that voting records (who voted, not for whom they voted) are and should be public record, but it seems somehow wrong to send those letters. Perhaps younger people, who are accustomed to sharing everything online, would have a different opinion.