That's right.
Insane people, OTOH, have no such restraints. That's what worries me more than any "terrorist" attack. I think we're paying too much attention to "terrorism", blinded as we are by the glare of media. But it's getting more and more easy for some doomsday cultist, sane enough to be able to perform basic engineering tasks, but insane enough to dream of a DIY Armageddon, to make those dreams (or, rather, nightmares) come true.
Even so, I'm still not sure whether withholding information is always good policy. Maybe it is - maybe a slight delay until defenses are built might be beneficial.
The odds of a random mutation unleashing deadly virus upon the world are probably close to 1.
It's amazing how quickly people have forgotten about the 1918 flu epidemic. It killed around 75 million people and infected more than a quarter of the world's population.
We're going to have another virus epidemic of that proportion, it's a question of when rather than if. We should be building defences because of the risk of random mutations and not because of the risk of engineered viruses.
Or a rogue government which probably has the ability to reproduce to the research relatively easily from doing so and providing the information to a terrorist group.
If someone wanted to commit an act of viral terrorism they would have done so by now, there are already plenty of dangerous viruses and hybrids in research labs all around the world, most of which have close to zero security.
I think the biggest thing that protects us again viral terrorism is that terrorists aren't crazy enough to use any kind of untargeted weapon.
Probably the most famous act of terrorism in british history - the gunpowder plot of 1605 was stopped because one of the conspirators tipped of a member of their family.
Terrorists don't want to do something that could well kill the supporters of their own cause or their families.