As of August 31, 2015, no live official trademarks were found on USPTO.gov for the exact term
Want for Free would be a great brandable for a company that specializes in creating freebie promotions for large companies.
Too expensive for a run-of-the-mill scammer/spanner, though.
Of course, there is no such thing as a free lunch, but most people haven't grasped that fact yet, which is how consumers get sucked in.
Even the local soup kitchen has an agenda, whether wanting to convert people to The-One-True-Religion or just trying to grab a larger slice the donor pie...