[nmeagent]

"I know you'll probably vote for $foo. If I check after the election and find that you did|didn't vote, bad thing $bar might just happen to your friends and family."

Edit: It's probably not a particularly good threat, but it could maybe be used to suppress certain targeted demographic groups that tend to vote one way or the other.

[Analemma_]

This seems like a pretty ludicrous threat to make. You could just submit a blank ballot or vote for the opposing party and your hostage-taker would have no way of knowing.

[nmeagent]

Right. It would probably be more effective for getting someone to just stay home.

[daemoens]

You would have to do that on a pretty wide scale for it to be effective and would be caught pretty quickly after going after just a couple people.