It's disgusting if someone from the forum has gone to the effort to make a complaint like that. It's got absolutely nothing to do with them. The work scheme provider also needs to realise that being out of work doesn't mean you forfeit your right to a personal life too. If you chose to partake in a hobby whilst you're out, then that's up to you.
One thing I should point out though. Have they actually defined that an individual from this forum has made a complaint? As we shouldn't forget that anyone can view the content on this board - member or not. It's all in the public domain.