There is a debate about this in a deposits thread: when I looked at the Circle T and C it said your real name was revealed if money was sent to you (not the name you put in the profile) someone else said they thought that was a defunct T&C for the American market.
I've used it once but if there is there is even the slightest possibility this is true I'm not using it again
OP - Obviously I recommend doing your own research etc, but I tested this out with my partner prior to using it with customers (I work in tech in my real life and still couldn't find a solution until this) and he didn't see my details so I'm unsure of which answer is correct (mine or the other posters). I have found it a great option for me, and as there's no fees you can try it out with a friend (or yourself if you have 2 numbers/emails) to make sure you're comfortable with the information sent/showing etc, and to see exactly who can view what (my first time we did a test with 5 pounds sent back and forth between us).
The post above had me questioning myself, and so I went back and looked into both mine and his accounts and sure enough he saw the name I made up for myself, the email address I signed up with, and no other identifying information. He put his real name in (typical male lol), so I obviously saw that. I looked around and so far as I can tell there's also no other options to go into where you can search for more information on the sender or receiver inside the site/app.
The only place they could possibly have (and therefore give) your information from - even in the event of emergency/investigation etc - is when you put in your bank details to withdraw funds, and even then it still works regardless of the name you put in so long as the account number is correct. This is what I did (fake but realistic sounding name - no sense raising red flags with anyone when you don't need to) and as I said I've been using it drama free for a little while now.
As with anything, only you know what works for you and is within your comfort/safety level, but I'd suggest doing the research and making up your mind on this one once you have all the information.
Good luck!
xx