I see the people there complain on other tokens as well. Strange!
Might have happened on an exchange as you mention.
Yes, and the more I dig the more I find that many others have been robbed the same way.
Sadly, I've just find out that my HVN are gone too... It happened 6 days ago. Both time, the token went out a few hours after I tested Etherdelta... and, actualy, they (BOT ?) sent them right away to... Etherdelta_2 contract 0x8d12A197cB00D4747a1fe03395095ce2A5CC6819
I don't say that the guys behind Etherdelta are involved in this but as we say in French "Il n'y a pas de fumée sans feu" (There is no smoke without fire).
Some ars... have probably found one or more breaches to exploit in a way or in another.
There are a lot of phishing scams out there trying to get people to log into MEW. Saw lots of them hit Slack a while ago. The best is to use a hardware wallet like Ledger Nano S or Ledger Blue and link it to MEW. Then your tokens cannot be stolen as you have to click a button on the device to authorize a transfer out. Those of you that got hit probably was tricked into logging onto a fake MEW site.