On , Dave Aronson (1:109/120) wrote to Kay Shapero:

 KS> In fact if a sysop is careless and doesn't do session level
 KS> passwords, the fugghead can even make up a fake packet 
 KS> with a fake backtrail and dump it on the system.

 DA>Any twit THAT knowledgeable and determined won't be stopped by 
 DA>much; if the locals put up barriers, he'll call LD....

They happen.  Everything I mentioned in that comment was based on things that
have occurred in the past.  All a pest needs to remain a pest is a list of bbs
phone numbers and a tolerance for high phone bills.  Of course, as the brief
career of "Arthur Werner" demonstrates, if you annoy enough people, eventually
one of them will find a way to deal with you.

 DA>Not a worry if the site HAS a lot of space -- as apparently many 
 DA>of the ones I have complained to, do!

With someone out there hawking a program for individually posting messages to
an astonishing list of newsgroups (instead of crossposting - the difference
between a 1 K message pointed to by 10,000 newsgroups and 10 Megs of
message...), they'll need it.....

 KS> However it's best to make sure you got the right target - 
 KS> frequently you get spams with forged returns.  Check path data.

 DA>On this side of the gateway, WHAT path data???  All I can check 

You don't.  Those on the other side do.  Or the gateop does if he has time.