The main spur behind this was a number of union activists and campaigns being kicked out on networks like Facebook and YouTube.

The mega-networks are trying to manage millions of active users with only a handful of customer service staff. Their limited time is taken up hunting paedophiles and phishers, so they largely leave the moderation to robots (the average revenue per user is so low, it's cheaper to lose a dozen users than to spend 15 minutes on deciding a case). Vexatious legal threats from companies (even where the argument is entirely bogus) are also great at getting campaigns on commercial networks switched off.

This puts many power users or campaign/business users (not just unions) in a tricky position. When you suddenly find you need to mount a campaign, you're friending like crazy and sending out lots of messages, and to Facebook's robots, you look like you've suddenly turned spammer, and you get frozen or kicked out when you need the network most. Ironically the more work you put in and the more you rely on your network, the more at risk you find yourself.

As you identify, this is one more attempt by a niche group to make the most of the power of some of these networking tools, but on a more sensitive footing, and for very focused aims. Most people thankfully don't live their whole lives as activists, and have a lot of other interests that they'll still need to use the big networks for - We certainly won't be giving up our Facebook cat (wildcat?) galleries just yet!

@interested_party - So far as I know, the site is planned to stay free for activists who want to make use of it, the same way all the other web services run by the volunteer group LabourStart.org have been for over 10 years now (a mix of voluntary contributions and making a little go a long way with Open Source).

How will it earn it's costs? Will it be free for the first 2-3 years then start charging a membership fee, like most unions? Unions do a lot of good, but they are also an attractive place for gerrymandering and dodgy deals.