CNNSI:
http://mlb.si.com/2013/11/27/hall-of-fame-voter-sells-ballot-to-deadspin-readers-to-determine-votes/
The identity of the BBWAA member who sold his or her ballot to Deadspin is being withheld for now, but Marchman says that this voter, “will announce his/her name and motivations once his/her vote has been officially cast.” The voter will still cast the ballot his or herself, but will do so according to the instructions of Deadspin, which will, in turn, determine how to vote by polling its readership. Neither Deadspin nor Marchman has given any indication as to how the vote will be cast. Indeed, the site seems open to any approach, be it an honest attempt to cast a merit-based ballot, or any of a variety of protest votes, such as a ballot containing only the names of players associated with performance enhancing-drugs, or one that writes in Pete Rose or the like.
So, we will get to find out who it was.