Hi Tekla, you are quite right, they are shadows actually just typed words on a monitor, but for someone who spends allot of time on these contraption trying to build up who they truly are, are also very vulnerable and open to being hurt by someones remarks.
To that person who is just starting out can be very self conscious and sensitive to the image they are attempting to project, so the antagonist on his/her monitor can be quite real, as though the person was right in the room with them, pointing their antagonistic finger right at their nose, accusing them of what ever.
I have been at such places, TS or just regular groups and when the crap started hitting the fan I usually just removed myself from that group.
Goodness knows there are thousands of other message boards out there, each with their own characteristics and personality, some good, some bad. Pick the one you like. I myself have found this one about the best as far as TS sites go, although it is not without it's antagonists either.
Cindy