Virgin had no option but to comply with the court order that was issued. If they had ignored it, they would've been fined hundreds of thousands of pounds - probably even more than that.
I'm not a Virgin Media customer, but I understand that the block is trivial to swerve around, so Virgin Media have obeyed the letter of the law, but haven't made it particularly difficult to get around. Anyhow, DDosing a web-site is just lame.