Is this only when using it as news or education etc. right? I movies need permission or get money for it don't they? Or Can you sell it as royalty free stock?
 read up on fair use, if the item is trademarked/copyrighted then approach the owner.
Me, personally, I always start by offering "product placement" advertising for a nominal fee.
(everybody these days has an autoreflex to distrust anybody that wants something for nothing, but feels victorious if they think they won you over on a good deal).Â
Ok I have a question. I have a clip I want to sell as stock footage on a disc with other footage. The clip in question has a group of people riding by in a horse drawn carriage. Most of the people in the shot I doubt you could tell who they are, but one lady turned and looked right in the camera as the carriage passed by in the shot.
Do I need to hunt this woman down and get a release so I can add this clip to the disc, or since this was shot on a public street, is it ok?
The carriage is the main focus of the shot. The people were tourist.
I did a quick look around (googled) and I couldn't find anything pertaining to stock footage. It is a rather awkward situation though and it appears, in the USA, that states can have different laws about using faces and likeneses.
For the last month or so I've bee reading about best practices on the http://www.centerforsocialmedia.org/Â website. See if you think that stuff applies to your situation.
 bruce