For people who have come forward, there are issues with 'testimony'. E.g. Voice replication -
The Architects of Intercept
While individual Lincolns scale linearly to monitor more than 1000 targets, these collection servers may also be networked to provide replication of intercepted
data to remote facilities.
http://www.ss8.com/pdf/corporate/SS8..._Intercept.pdf
THE PLACE OF FORENSIC VOICE COMPARISON IN THE ONGOING PARADIGM SHIFT
This is a shift to requiring that the evaluation of forensic evidence actually be scientific, including that the reliability of methodologies be testable, and requiring that forensic evidence be evaluated and presented to the courts in a logically correct manner.
http://forensic-voice-comparison.net...hift%20v15.pdf
Notes On The Discovery, Collection, And Assessment Of Hidden And Dirty Data
Gary T. Marx - Massachusetts Institute of Technology
What do ABSCAM, the Santa Barbara Oil Spill, and the Freedom of Information Act have in common? Or what do blackmailers, police, priests, journalists, and some social problems researchers have in common? (Perhaps we'd better not answer that.) In the first case, aside from what they may communicate about the pathos of the last decades, each represents a means of collecting hidden and dirty data. These means are experiments, accidents, whistle blowing, and coercive institutionalized discovery practices. In the second case, we have actors who routinely deal with discovering secret and dirty data.
http://web.mit.edu/gtmarx/www/dirty.html