[fapjacks]

In some instances when served with an NSL (or some other mechanism we don't even yet know about), they can be forced through legal policy to cooperate in building something that pwns your box. Google's compelling reason is that they are under the jurisdiction of the American government. Though I share your tentative belief that Chrome/ium isn't necessarily a "pwn vector" per se, I am 100% willing to believe that they are compelled to cooperate in building some kind of vector for the NSA.

[grrowl]

You say "they" as in Google, but it would be much more effective to persuade a single developer (and maybe his manager) who can implement such a feature in a open, transparent way (which would display the standard "recording" icon in the omnibar) or in a closed, subversive way (like, this).

Basically lean on "Never attribute to malice that which is adequately explained by stupidity" as much as possible to fly under the radar as long as possible.