The Electoral Commission is warning people not to tweet political advertisements on election day. They have a cast-iron legal case - the law prohibits attempting to influence voters on the day, on pain of a $20,000 fine - but at the same time its obvious that its a bit of an ass. Our electoral law was written back in the dark ages, when the internet meant "newsgroups" (remember them?), advertisements needed a printing press, and so could easily be controlled. As British judges have just learned over superinjunctions, the world doesn't work that way anymore, and attempts at suppression can simply result in mass rebellion. The only way publication restrictions hold anymore is if people want to keep them.
So, rather than making empty threats of enormous fines - because let's face it, the Electoral Commission wouldn't be able to prosecute everyone, or even a reasonable faction thereof, if the law is broken - I'm going to try and convince you to obey it.
The restriction on election-day advertising exists for a simple and very good reason: so the day belongs to us, the voters, not to the politicians. It means we aren't bombarded with advertising while we are trying to make up our minds. It means we aren't harassed by sign-waving hacks when trying to get to a polling booth. It means we don't have to put up with the very worst politicians have to offer in a desperate, last-ditch effort to influence us (and they will save their worst till last, when the returns are highest and the costs lowest). In short, it means we can vote in peace. They've said their piece; now we get to judge them on it.
And it works. Election days here have a carnival like atmosphere. Freedom from politicians IMHO contributes to this. That, and a strong tradition of election-night parties.
The law is not difficult to comply with. As a blogger, I've done it for the last two elections. Say my last words the night before, ask people not to post infringing comments (back when I had them), and don't blog anything that influences voters until the polls have closed. This year, I'll do the same. As for Twitter, I'll probably tweet that I'm going off to vote.
As for people who want to tweet "vote for Foo!", that's what a "Block spam" button is for. Because that's what they will be: spamming hacks, a botnet made of meat cluttering my feed with irritation. And any party who organises twitter spam on the day deserves to be nailed for it - not just under electoral law, but antispam law as well.