what i mean. i have in poloniex some altcoins... ok?
i have them because i want to trade. if they get hacked or anything else i loose....right?
how can we avoid those things?
When you are using exchanges you trust their operators. That is a risk you have to take into account. You cant go around it till there is a decentralized exchange.
The only solution is to trade otc. Or at least send the coins to exchange, trade, send the coins back to your wallet. Every time and ASAP.
It has happened before, it is happening now, it will happen in the future. When you trust someone there is always the risk of getting scammed.