I wouldn't bother with a release. The chances of people recognising themselves are close to zero and even if they do, the chances that they will even consider doing anything about it are also almost negligible. If you look at postcards for sale of normal tourist places you will see that many have people in them of a similar scale to yours where they are in the scene but are not the subject. I doubt that the postcard manufacturer has releases for any of them.

Quote Originally Posted by Worker 11811 View Post
Unless I was using a zoom lens to home in on some chick with big knockers, wearing a bikini there is no expectation of privacy.
Let me know when you start selling those!