Watch for the Union Label

(Fox News) - On any given weekday here in Washington you can see several construction sites being adorned with picketers protesting the use of non-union labor.

But the Washington Post reports many of the picketers are not even union members — but homeless people, retirees or students being paid slightly more than minimum wage — with no benefits.

The Post says carpenters unions across the country are using this tactic — which is not going over well with some of their union brethren. And advocates for the homeless say the unions are taking advantage of the unfortunate instead of helping them.

Says one shelter official — "These jobs won't pay the rent. If they're out there every day Monday through Friday, when are they looking for a job?"