I logged into the connect.securifi.com portal and saw the option to block users, I tried to block a rogue iphone on my wireless but it still said 0 devices blocked. I noticed the save icon and pressed it but it still says that there are 0 devices blocked.
I tested on my phone and sure enough, it kills internet access, but it doesn't register on the portal or on the touchscreen that my device is blocked so I can't unblock it. I realize this is a newer feature that securifi is testing out, this seems like it is still a WIP.