Ish. If Facebook violate the OSM licence, then that's illegal and something could be done about that. Though the OSMF would never be able to seriously legally sue Facebook. One side has considerably more money than the other.
But if Facebook abided by the OSM licence, but did things the OSM community really didn't like, the OSM project could shun them. Not accept sponsor ship, block FB's RapiD software from making map changes, eject them as a corporate member from the foundation, etc. They'd still be able to use the data, but they'd be a persona non grata.
But if Facebook abided by the OSM licence, but did things the OSM community really didn't like, the OSM project could shun them. Not accept sponsor ship, block FB's RapiD software from making map changes, eject them as a corporate member from the foundation, etc. They'd still be able to use the data, but they'd be a persona non grata.