So, yes, you could totally do it. You'd just have to never, ever get caught.

Exactly. There are more subtle ways to go about controlling the population. Methods that do not have the constant risk of rioting if revealed. There is a good reason that overuse of Forking is considered a social faux pas in the Inner System, because the Hypercorps know that control of the labor supply is paramount to continued profit. So they released the memetic engineers to run propaganda campaigns that highlight the dangers of forking in a catchy, jingle soundbite. They do the same with Uplift/AGI rights. And why New Economies are dangerous places to live. And how people on Titan are slaves to the social majority. They already control how the masses think and live, why would they risk all that for a little bit more control? The profit is already rolling in.

Mindcontrol costs resources. If you want to brainwash your population you need to maintain the drugs, psychologists, psychosurgeons and other systems, as well as accept the unavoidable costs of occasional failures and outside opprobrium. Also, most societies in Eclipse Phase are open (yes, even the PC - check out the description in Sunwards): people can and do comment on what is going on, criticize rulers and read the fine print in government reports. It is tricky to get mindcontrol onto the agenda without a lot of people discussing it. That said, given the nature of governments they will want to have a mind control monopoly. And once you have such a great tool, why not use it? (I have personally heard a senior UK civil servant say that she liked the drug-based mind-control options in a particular future scenario we created together) There are mentions in Sunward of secret experiments in social control using various means, and I can imagine various groups looking for better ways. For example, instead of mindcontrolling everybody, why not put in a few shills that knowingly or not are the eyes and ears of the government in the population, influencing their neighbours with their guaranteed views? I am pondering writing an adventure where the PCs visit an autonomist habitat gone bad. Some people were concerned that the citizens were not cooperating enough - they were misbehaving like normal humans do, not living up to the high visions of the autonomists. So they began introducing a bit of artificial help. The idea was to induce a larger "circle of concern" and stronger altruism using a oxytocin-like drug that infused everything in the habitat. It worked: people began to trust each other more and feel goodwill to strangers in the habitat. Except that it also strengthened an us-vs-them mentality: habitat citizens are good, everybody else are suspect and can be pushed aside by the interests of the habitat. http://www.sciencemag.org/content/328/5984/1408.abstract The synthmorphs were the first who were declared unmutual and removed. Then the few holdouts/immune biomorphs were forcibly cured using psychosurgery. So now we have a habitat of fiercely loyal xenophobes...

Forgive this if it sounds like a crude mockery of the organization but it must be said: The United States of America is also an open society, with people commenting, criticizing rulers, and reading the fine print. Even I, a Canadian citizen, was able to read the entire 1000-some-odd page medicare bill when it came out (I had a lot of time on my hands, then). It doesn't eliminate the fact that just shy of 20% of people in the United States (according to a Pew poll) believe that their president is a Muslim because of talking-head media pundits. A blatant lie, easily exposed by five minutes of research, is heartily accepted by a fifth of the population. This is just one example, as well; there's plenty of examples of incredible tactics developed through public relations to control people. Even things like Embedded Journalism only exist as a control tactic. You don't need drugs for mind control; just repeat things enough, make sure that mainstream media doesn't seem TOO biased, and eventually people start to believe anything you tell them.

"I was thinking along the lines of introducing a subtle MC nanovirus in the cortical stack, for instance." Psycosurgery needs to be tailored, everyone is a perfect unique snowflake.