Photo sharing on Tumblr?

I've recently gotten into Tumblr and I really enjoy posting photos. The ones that I've posted so far are edited photos of like cherry blossoms, beach scenes, flowers, etc. Am I allowed to post photos with people in them? Not where people are the focal point, but let's say that I want to upload a picture of a boardwalk scene, with tons of people in the picture. Would I be allowed to do that, or should I just stay away from photos with people included in them? Thanks.