Allow admins to block members by username and IP.
I back this idea.
Recently I had to block a user for inappropriate behaviour but I had no option to limit his account for sending or receiving messages or akin for the time his funds are cleared. Once funds cleared, he withdraw them and then permanently Deleted from site.
Please do that quickly.
It is need must.
Mh Plaban commented
there should be some option to identify fraud user and ban them permanently or temporary