Facebook already scans every private message.
Imagine the NSA does too, but it is probably still illegal to admit it, let alone execute police enforcement based on a private message. It is still important that we keep snooping on private messages illegal even if they secretly do.
What about Google? The information available from gmail and google searches could put an insider trader on easy street in a couple of weeks. The information available would make Pelosi look like an amateur.
How does Google keep their employees out of this data?