If computing devices of US Senate Intelligence Committee can be undetectably spied upon for unknown amount of time, and Snowden –  as he sweared – could read the emails of any member of the Eu Espionage parliamentary committee, then is anyone safe in the civilian world?

How many people and actors can have such access in illegal ways?

How likely is it for abuse to be discovered by external reviews?

How can we ever estimate that? Can such actors also undetectably tamper placing false evidence?