once i have seen page of switching videodriver on. there i have seen that were written that driver's are checked. i have just opened that again but it is not written now. may be i misremember somehow, may be that is written in other description in other place. now there is only written that that closed driver decreases stability and ubuntu developers cannot improve it, as i remember.
that time i thought "what means checking"? and searched for checking against spy activity and vulnerabilities and have not found, only about checking that they work stable i.e. not crashing and not incorrect somehow visible.
as i heard there are some antivirus software [in the world] that can check binaries not searching virus signatures, but analysing binary program directly against bad activity, i think may be it is indeed possible to check whether binary program sends information from keyboard to the internet for example (i.e. i want to say about keyboard spy). but though this type antiviruses are closed source theyself i think. so this post will probably be downvoted i think, because that is impossible to do well nowadays.
what closed source binaries used in ubuntu i can say for example: nvidia, flash, opera, skype, google earth, vmware.
10th january 5:12 gmt:
that requires artificial intelligence or human analysis to work well enough. and checking programs would not be complete checking, because chips are closed-source.
16th january: and now i have seen apparmor. now i think, (i had forgot that), no need in that, closed-source binaries can be properly sandboxed.