Back to the original question - not a lot from what I can see. Last year we had local elections and everyone I know voted. The process went to round two and many didn't bother voting again, including my lesser half, to-date he hasn't even received a letter slapping his wrists.
On the other hand my Greek teacher was supposed to help with the vote counting, on round two, but was never informed of the fact. Quite happily she went off to Athens for the weekend only to get messages and phone calls telling her the Police were looking for her!!!
Not sure of the position when it comes to a General Election, they may view this more seriously.