The point you raise is very valid. People forget the privacy issue
as being very important. (That's one problem I have with Troi, I'll have
to grudgingly admit; there she goes, intruding into anybody's and
everybody's mind without even so much as a by-your-leave, including
aliens they've just met, as well as humans. Mind your own business.)

One other element to consider in all of this is real simple: at the
time in question, it's possible to alter one's memories. (Remember,
Sinclair is missing 24 hours from his memory.) One can blank certain
memories. So it's possible that a person who committed a murder might
pay big bucks to have that memory wiped. Then you have to be sure to
find a telepath who's good enough to see the "seams" (for lack of a
better term) in the person's memory to know it's been modified.

jms