The Party did. It raised over £9,000* in the last couple of weeks from supporters. Which is great... but just getting preliminary advice over the last couple of weeks has cost £1,600, and fighting this case to trial could cost hundreds of thousands of pounds. While it might be possible to raise that money, the feeling seems to be that it could be spent better elsewhere (although, of course, those who donated to the legal fight should have already been emailed to explain how they can get their donations refunded).
I find it particularly ironic that we are told pirates are stealing money/income from artists etc., but it turns out pirates don't have that much money - whereas the BPI Ltd (all of whose funding would otherwise be going to artists etc.) seems to have plenty of cash to throw at lawyers and legal actions.
*But less than £10,000 - you can't make this up...
[Disclaimer: I am a member of, and work for PPUk, but was not one of the individuals sued.]