Solidarity for 8 bucks an hour

In my true nerdy way I was catching up on my npr news and came across this article.
This is fascinating. In Washington D.C., the "Mid-Atlantic Regional Council of Carpenters" are picketing outside of work sites because they are demanding the going wage of $24.00 per hour. Sounds good to me, they are only making $15.00 to $16.00 per hour currently. Here is the weird thing.

The Union has hired homeless people to do the picketing instead of the Carpenters. The Union is paying the homeless $8.00 per hour to walk around with the signs and give very general information.

Doesn't that seem wrong to you? If I was in a Union, and I was going to strike, shouldn't I be walking the picket line instead of a hired homeless guy? Solidarity for 8 bucks an hour.Oh mylanta.