That's the argument put forward by Simon Crosby, chief technology officer at Citrix. An airliner has millions of parts, and so does a large data centre. A few providers can put them together reliably, but "you can't," he told his audience at the Citrix Synergy conference in San Francisco.
Crosby pointed to attacks by Anonymous on organisations such as Amazon Web Services (AWS), PayPal, Mastercard and Visa in retaliation for their treatment of WikiLeaks. AWS "didn't blink" he said, but the other companies running their own data centres suffered outages. "An attack on your data centre will take your outfit down," warned Crosby.
That doesn't mean a big, properly configured public cloud won't fail. Crosby pointed out that Gmail, AWS and Microsoft Online Services have all had outages recently.
The trick, he suggested, was in learning how to use public clouds so that you can keep running in the event of an outage. When AWS went down recently, Netflix kept running despite being 100% AWS based.
But you can't do that with legacy applications, Crosby warned, but you can with next-generation applications, so organisations need to find people with the skills (such as Ruby on Rails) to build them.
A related issue concerns isolation. The development of OpenVSwitch - a high-performance, secure virtual switch - provides isolation, resource control, visibility and security in a multi-tenant facility, he said.
IT departments have never managed to protect or control their organisations, he said, so they should leave that to someone that's good at the job and does it full time. "[There are] so many more layers of protection" in a public cloud, and the operators have more resources to fall back on.
Crosby also implied that cloud or data centre security is not the weak point. Attempts to illicitly extract data from them are rare. What's more common is an employee taking data (think WikiLeaks again), or attacks at the client level (eg, RSA was compromised via a Flash exploit, not by trying to obtain information directly from a server; and the well-publicised attack on Google was via an Internet Explorer 6 vulnerability, not on its cloud infrastructure).
"Unless you protect the client, you can do nothing for the cloud," he said, but "You can't just do cloud [security] and not the client" or vice versa - both are necessary. "Securing execution in the cloud? I don't think it's a big deal [to do]," and a cloud vendor will probably do a better job of running applications securely than a typical company can.
Disclosure: the writer travelled to San Francisco as the guest of Citrix.