The unspoken rule is that people can usually count on the smartest among them to make good decisions and avoid putting lives in danger. If scientists were expected to risk catastrophes each time they put on their coats, then they probably wouldnt have made it very far. But there may be an outsider or two in the world; to the layman, bringing an old virus back to life sounds like one of the worst ideas imaginable.
There is a method to the madness, of course. Concerns over climate change have brought up the issue of prehistoric viruses once frozen, but thought capable of infecting and even harming humans if the ice that encases them melted. Because of that, scientists have opted for some early prevention. With a sample of one of the extra-large viruses in their midst Mollivirus sibericum the plan is to place it in a petri dish and see how it responds when a fresh host is in range.
Naturally, that would mean the scientists would run their tests in safe, enclosed environments and more importantly, begin their tests only after its proven the giant viruses could pose a threat. It sounds like a disaster in the making, but its worth considering the alternative: if the viruses made it out into the real world unfettered, then that could be the real disaster.