The "safety" of the cloud is about two things: 1. trusting your service provider, and 2. redundancy.
You have to trust your cloud provider. They control everything you do. If their security isn't bulletproof, you're screwed. If their SAN's firmware isn't upgraded properly to deal with some performance issue, you're screwed. If their developers fuck up the API and you can't modify your instances, you're screwed. You have to put complete faith in a secret infrastructure run for hundreds of thousands of clients so there's no customer relationship to speak of.
That's just the "trust" issue. Then there's the issue of actual redundancy. It's completely possible to have a network-wide outage for a cloud provider. There will be no redundancy, because their entire system is built to be in unison; one change affects everything.
Running it yourself means you know how secure it is, how robust the procedures are, and you can build in real redundancy and real disaster recovery. Do people build themselves bulletproof services like this? Usually not. But if you cared to, you could.
You have to trust your cloud provider. They control everything you do. If their security isn't bulletproof, you're screwed. If their SAN's firmware isn't upgraded properly to deal with some performance issue, you're screwed. If their developers fuck up the API and you can't modify your instances, you're screwed. You have to put complete faith in a secret infrastructure run for hundreds of thousands of clients so there's no customer relationship to speak of.
That's just the "trust" issue. Then there's the issue of actual redundancy. It's completely possible to have a network-wide outage for a cloud provider. There will be no redundancy, because their entire system is built to be in unison; one change affects everything.
Running it yourself means you know how secure it is, how robust the procedures are, and you can build in real redundancy and real disaster recovery. Do people build themselves bulletproof services like this? Usually not. But if you cared to, you could.