I've been on Steemit for 2 weeks now, and this morning when I tried to log onto DLive to up-vote someone's performance there, I noticed that SC came up, and then DLive wanted my owner or active key, and would not accept my posting key. So I backed out.
I'm not sure if what you've written about here would be related to this? When I did a search for "why doesn't DLive accept posting key" yours was one of the articles that appeared. One thing for sure, I'm glad I read your post, because of your revelation that these guys can take over any account! It was only my newbie caution-inspired knowledge to never use our active or owner keys for another site, that saved me from what you've written about.