How so? People were told to use online seed generators. Yes, a seed, online. Not from the wallet itself, no password, not protection at all. And one clever chap collected all the generated seeds and just cashed in.
I really do not understand why people are so dump enough to use a online seed generator ,is it that hard to create your own rather than trusting a third person and that too from a random site,i am not aware of the coin so basically people are just dump and you cannot complain about it to anyone for being stupid,but if the team behind the project encouraged people to use it,then they might be liable to the situation.
Are they any offline to keep the IOTA safe. For bitcoin and some altcoins may be supported by the hardware wallets but the IOTA and all not accepted by the hardware as much my knowledge. As op said if the wallet for IOTA alone empty means you have to understand there is attack by the source coder site or hackers involved in the core development. Other than trying to hack on cheap altcoin is not a possible. Hackers will have worst time try on the online wallet sites.