This is in no way confined to polls. Almost every website has a voting component of some kind, be that measuring which stories are read most, allowing up/downvotes, Q&A or comment systems etc. It doesn't have to be a straightforward poll to be gamed.
I think it would be better to address the malpractice by our governments than to blame journalists - if the gov. is sufficiently determined, and is given the funds to spend on it, they will find ways to distort online discourse. The UK has just increased funding for 'intelligence' (what an oxymoron) by £800 million, so you can expect more of this to come, and we should lay the blame where it belongs - with those agencies poisoning the well of online discussion.
I think it would be better to address the malpractice by our governments than to blame journalists - if the gov. is sufficiently determined, and is given the funds to spend on it, they will find ways to distort online discourse. The UK has just increased funding for 'intelligence' (what an oxymoron) by £800 million, so you can expect more of this to come, and we should lay the blame where it belongs - with those agencies poisoning the well of online discussion.