One of my classmates asked, "Where did you get your DNA?" I'd assumed he was using natural DNA which matched the patterns he needed. Nope. Turns out there were services which synthesized DNA to order. Email them your sequence (CTAGATAACA etc.) and they'd FedEx you a vial of newly-manufactured DNA, precisely to spec.
A rare, limited service only available to qualified research professionals? Maybe five years ago--but a quick visit to Google turned up dozens of labs willing to provide you with the DNA of your choice. Note the guarantee of absolute confidentiality.
Like most industrial supply companies the pricing is a bit obscure. How much is "$1.10 per base pair" for real work? It means something the size of the Ebola virus would cost $20,790. Well within the reach of a terrorist group. Hopefully the good folks at Celtek do screen their customers.
At this stage of the war I don't think we're in that much danger from terrorists wielding customized versions of Ebola. There's easier ways for them to attack. But it's an option now, while it wasn't twenty years ago. The part that scares me is extrapolating this curve another twenty or fifty years. What happens when DNA synthesis doesn't take a dedicated laboratory, but can be done with a desktop machine? As Moore's Law keep cranking along this will keep getting cheaper until it's within the reach of the script kiddies who commit high-tech vandalism today.
Teenage vandals aren't likely to wipe out cities on purpose. But the most damaging attack on the Internet did its harm through an error by the author, not through malice. Worse than that could be an overlap between a script kiddie and the spontaneous rage which produced the LAX shooter and Seattle shooter. The Oklahoma City bombing was a foretaste of what lone terrorists with technological skills can do.
This is why I believe trying to maintain the global status quo is impossible. We can survive the occasional Tim McVeigh. Having whole nations in favor of blowing up schoolchildren in a world with desktop WMDs is unsurvivable. We need to shift cultures that advocate killing the innocent to ones that abhor it. This doesn't require achieving utopia. Bringing Iraq, Iran, Palestine, etc. to the level of democracy in modern Japan or New Zealand would be nice, but what we really need is to get them to the level of Turkey or South Korea in the 70s or 80s. Places where young men have better options than strapping on a suicide belt, and their families encourage them to do something productive. Then we can all happily mind our own business, or at least not mind foreigners and give our neighbors the limited attention needed to spot McVeighs.