Tor Browser's Private Browsing Mode breaks sites.
Users are getting frustrated when they can't log in to certain sites. An example is en.mail.qq.com, which says you must have cookies enabled before it rejects your login. Disabling private browsing mode in Torbutton fixes this issue, but not many users know to do that.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information