Recently OgNasty bitcointalk account password changed and OgNasty can not Access his Bitcoin acount ...

Before any other thing, what are you trying to find out? Are you trying to act like a monitoring spirit? To monitor his movement? Monitoring the very action of a top member of the forum like when he changes his password or takes any step in his account to report him doesn't make any sense.
In my country, if you do this kind of thing without proper backing, you will be questioned seriously for not minding your business and spreading misinformation
There is a chance he happened to stumble on the fact OGNasty changed his passport by pure coincidence or chance.
It is public information, after all, anyone can have access to it. Even I have spent some idle time checking some prominent profiles on BPIP, like satoshi's and those that are most recognized around here, it is a matter of curiosity on statistics.
So in that aspect, we do not have further proof this person is actually stalking or following OGNasty's stepf on the forum.
This is one of the best lessons for those people around the community who spread or planning to spread their own perspective about a specific things. And also we need to (THINK BEFORE WE CLICK). which means it's better to do some research and think if it's gonna okay if we gonna make a topic like this or think that no reputations involved. Also we need to know that If someone got hacked then for sure they will create a new account and share their experience here in forum which is it's we need to mind our business and not others if don't have any statement by the owners.