Anyone who was paying attention before Snowden knew there was mass surveillance happening. See Room 641A, Stellar Wind, Quest Communication's refusal to cooperate, etc. These were all reported well before Snowden in major media such as the NY Times, LA Times, Washington Post, etc. I remember many of these were first reported back in 2006.

On the other hand, no reports on CIA programs selling crack cocaine to the inner city have ever been described or verified by any major media outlet, as far as I am aware[1]. Nor have I seen any convincing evidence of such a program.

But I'm open to any evidence you can show me, if you have any.

Also, as someone else pointed out, MI6 wasn't founded until a half century after the Opium Wars.

1. Despite many major media outlets—the same ones who outed programs like Stellar Wind—investigating the claims that the CIA smuggled drugs into black communities, they all found that there was no evidence of such a program.