I can not know for sure, but I doubt that this worry is on their mind. By the time these machines are reliable enough to do prime factorization, we would have had plenty of opportunities to move to "post quantum" public cryptography schemes that are as resilient to quantum attacks as they are to classical (cloudflare and google chrome have already implemented experimental HTTPS variants that are resilient). I doubt that Shor's algorithm would ever be a "killer app", because only a small fraction of encryption algorithms are susceptible to such an attack (it is not too far fetched to say that it is just a historical happenstance that our standard public encryption schemes happen to be susceptible).