I have had a couple of questions concerning the ownership of the content you upload so I thought a quick answer was is in order. In almost 100 percent of the time if you created it and you upload it, you own it. It is not 100 percent because the question is about content that is uploaded. In our new world not everyone believes in uploading their own content. If you created it and did not do it for hire than you own it. There have been some sites that I have heard of telling you in their TOS that they get ownership of the content. I have not found one yet.
What you do is give them a license to use it. The issue you might have is the TOS and what license they make you give them. Read it carefully. If in doubt contact an attorney. I am not one. Many sites require that you to give them equal rights to you with a couple of twists. Most of them require that you cannot cancel their license even if you cancel the membership. They also have the ability to sell the license, trade it and market the products without any input from you and with no compensation for any use. That part could be expensive to you and you have not claims for anything including copyright infringement.
That is the grist of the content question I received. I hope this helps clear things up. Read the TOSs carefully and all of it. Not just the content area as many are or have moved some of the things they can do to other areas of the Terms of Service. It might be in their privacy policy for example.
Just be careful, know what you agree to do and if you do not agree, do not upload anything,