Frostbite has it in one. Now for a "model" or commercial shoot, (though I still largely stay with Airfix) you would need a Model release form to effectively sign away their rights to the photographer who still holds copyright. I think that for commercial premises, locations etc. that they also have rights which border onto and maybe into intellectual property rights. It is a grey area in which m'learned friends would throw much enlightenment (God - Did I really say that?) and at a cost to knock your socks off no doubt.
The first and most valuable tool however, is common courtesy and it is free too. If anybody objects, then an apology and the removal of any images from wherever specified, will hardly ever fail to do the trick.
Conan