The cloud mining scam sites that you are talking about who shut down after receiving decent deposits, are nothing more than shitty sites that are being operated by a few noobs who get excited by just a few thousand bucks. If we look at how certain cloud mining services are operating, perfect example is genesis mining, they don't have to shut down in order to scam people -- they can keep paying out till a moment comes your contracts will get terminated due to them not being profitable anymore. Funny thing is that a lot people here consider genesis mining to be a legitimate cloud mining service -- just shows how delusional people here are....