Yes, they are, they are easily 51% attackable too but the bad thing is that the whole market is falling hard (it seems network security is not so priced in first minable coins or XRP consensus system), starting from BTC. We have just had another major volume drop in last hour, back to 6,7 in no time. Unfortunately coins fiesta seems over. Exchanges obtaining banking is not enough it seems, moreover many whales are using those banking link to sell and cash out in stead of buying. Strange thing hashrate keeps climbing (near 36K PH/s BTC alone), so miners are betting on a bull run or they have received equipment lately after buying during FOMO and trying to cover costs. If the drops continues it won't be profitable anymore btw and things will get really bad.