Some interesting questions there, Ralph.
As a regular contributor here, I can perhaps start by saying I'm neither paid by or a member of any political party, although clearly I have some political views, which get expressed. Some other contributors I know are members of political parties, but they won't be paid for their contributions, and the fact of any party membership seems completely irrelevant. Political parties are a natural result of how we do democracy in this country, and membership of them is perfectly respectable option for anyone who wants to contribute to society.
I doubt very much if Forums such as this are under the sort of attack you describe, though I'd be interested to know who your two suspects are - pm me if you prefer not to go public here. One reason for saying this is that not many political parties have much money at the moment, and another is that Forums such as this are probably not the best of the new media for influencing opinion in the sort of controlled way you seem to fear, from your use of words such as 'under attack'. Because they are open to anyone starting new threads and commenting on others', they sometimes get side tracked into frivolity, so obscuring a serious message, or maybe worse from the point of view of any would be political control freaks, dubious messages can be instantly shot down by reasoned argument.
On the other hand, there is serious money interested in knowing how to use these new media, and I think it significant that a recent Networked Neighbourhoods conference I attended was hosted by a leading PR company, and that one of the subjects under discussion was the use of 'hyperlocal sites' for marketing. But the impression I got was that they hadn't quite worked it out yet. For the reasons given above, if any of these new media can be used in a controllable way for either political or commercial purposes, I suspect it's more likely to be Facebook, Twitter, or blogs where comments are either disallowed or moderated to such an extent that they might as well disallow comment altogether.
There's also a reasonable public sector interest in Forums, which is well expressed in this YouTube link from Lewisham Council's Liz Dart -
https://www.youtube.com/watch?feature=pl ... 3hJsJjoR5g, in which she says how Forums such as this should be used, not least because they are cheap, but recognises that the Council should not try to control them, because they can't. On the other hand, she also mentions efforts to set up some web site in Crofton Park, which so far seems to have come to nothing, and I believe there is - or was - Council money available from the same budget to set up local sites from traders organisations in Forest Hill and Sydenham - of which again, there is little sign. So even though the Council sort of knows it makes sense to use sites such as this, institutionally it may be hard to let go of habits of control.
There have been discussions here about whether Forums such as this are losing ground to these newer media, and to some degree they are - the massive rise of Facebook makes this inevitable, and one of the reasons for its rise is that it feels friendlier - you can turn off messages from people you don't want to hear. Facebook is also a rather profitable company, with money to invest in making it all the more attractive an experience to use.
I don't have a particular problem with Facebook, Google or any longer established companies in the older media trying to make money to pay staff and shareholders. But I think sometimes misplaced frivolity, flame wars and trolls are a price worth paying for the sort of real openness of discussion which Forums such as this can provide. It's a paradox, if you like, that because of these strengths, Forums retain their credibility even with a lower market share, so will continue to be under attack from anyone who wants to control opinion. But because they can't, on Forums, they achieve nothing more than anyone else with more or less reasonable points of view who choses to post here - in which group I include myself.