While I am sure there will be some pitchforks and torches for this, it seems mostly harmless to me. One of the most common objections to GM crops goes something like "what if scientists add a peanut gene to my tomato? I am allergic to peanuts!" (What is 'a peanut gene' anyhow? Genes code for proteins, one gene won't give that tomato a shell - and as an aside, if you're allergic to aflatoxin from mold that grows on peanuts, that won't be a problem either). So knocking out genes isn't be adding anything to the plant. I'd still like to think we'd do some testing, but it seems generally likely to be safe...
Weaponized crops aside, it's also worth considering about all of the problems that have arisen with invasive species. What happens if a plant bred for it's resilience begins to choke out other crops? What about the problem of creating mono-cultures, either intentionally or inadvertently? And those are just the obvious examples of what could go wrong.
Not to say that there isn't a lot of potential for good with these technologies, but I don't think that companies doing an end run around the USDA, or any other regulatory body that might catch potential problems, is all that harmless.
That would require making peanuts resistant to Aspergillus sp. which would probably involving adding, not removing genes (but I am not a geneticist...).
