New ticket opened - http://dev.deluge-torrent.org/ticket/2359

I'm also surprised that nobody has notified you about this.
What is next steps in resolving issue, how can I help? Should I register it in bug-tracker?

Passkey leakage. Some people reported that theirs passkey was stolen after using Deluge. In conversation with tracker admins they mentioned ( administrators ) that Deluge has vulnerability allowing easily stole user passkey. http://translate.google.lv/translate?hl=ru&sl=ru&tl=en&u=http%3...

On which trackers you got the error message?
As I noticed, that Deluge is blocked on some huge trackers due to passkey security issues they found.