I can't tell you how happy I am to find this thread. This happened to me yesterday. The account is invisible, but has not been suspended. It's named 1 and when I searched for that name, I blocked the account that came up. That usually removes the notification from my list, but not this time. This time it only hid the notification until I got another follower. At no time will it let me click on the 1 notification so I can go directly to the account and block it. It's insidious!!! The reason it's freaking me out and I'm desperate to get rid of it is that I've been cyberstalked since July 2014. Twitter has done nothing to help me. Please, if anyone knows of a way to see an invisible account and/or remove it, share your knowledge. I took screenshots of each time it's appeared in my notifications. It reappeared just hours ago. Please, help. Thank you.