[Security] Hijacked community at SNS.

Mixi the most populer SNS(Social Network Service) in japan.(Like Orkut by Google)
in this SNS some community was hijacked.(community whith huge number of menber joined)
hijacker's technique are Social engineering.

Three Techniques are below...
1.hijack community with no owner(owner has leaved SNS)

2.Send message directly to Owner "I want to be owner"
(these community are not Active)

3.Two or more malices members ruins the community.
Malicious members blame owner because owner is not steady.
The person who runs for a new owner goes out , saying that "I become a owner while it is getting ruin".
A tired owner is cheated and transfers the management right.

After hijacked they modify content of community.and delete Bulletin board messages...they renew community.

they enjoys the reaction of the member who is from the origin.
or
It enjoys counting the seceding number of people.

Real Example is...

"Mos Burger" (hamburger shop's community) was hijacked and community contents has been changed to tavern community.

And now Mixi created sub-owner function to defend community to hijack.
A sub-owner might be able to obstruct the hijack.

infomation from
Mixi community Hijacker's infomation site.(Japanese)