Two weeks ago I participated in a conference in which a computer engineer for British Intelligence (MI5-6) was present. The conversation turned to recent events and he asked me if I had any ideas. I said, "I think the people have shown that they are amenable to instruction and will cooperate. I don't know if surgical sterilization is practicable on a global scale, but personally I would rather get cut than be injected with God knows what. We do have a problem with rapidly escalating population and standard of living, something must be done, but this problem is so big, to deal with it in an underhanded manner..." and left it there.
The next day my dog came home branded on the groin. This tells me that the idea might be worth exploring, but because so much money is invested in underhanded sterilization methods, e.g. vaccination, it would encounter opposition.