Terms of use, Rights you license[1] (emphasis mine)
"In order for us to provide you with our file transfer service we require you to grant us licences in respect of the files you wish to transfer. Specifically, when you upload a file to our site, you grant us a perpetual, worldwide, nonexclusive, royalty-free, transferable licence to use, reproduce, distribute, and perform that file to enable us to transfer and store your file; and the right to sublicense this right to third parties. We claim no ownership or knowledge of content of your files as we only require what is necessary to facilitate your file transfer."
Sounds sketchy to me