On Sat, 10 Apr 2004, Scott Call wrote:
My point was that my $20 GE telephone cannot be made into a liability for my telephone provider without my explicit participation, whereas a $20 a month dialup (or $50 a month DSL, etc) customer can be a liability for me just by being turned on.
Although Bell Labs avoided publishing papers about weakness in the telephone system, it doesn't mean they don't exist. The Communications Fraud Control Assocation has a decent publication on communications fraud. http://www.cfca.org/CCSP_dictionary_orderform.htm They cover numerous opportunities for mischief which can occur with your explicit, implicit, and even without your participation. In most cases it is the equipment connected to the line (i.e. CPE), not the line itself vulnerable to mischief. An answering machine with a default remote access code, a cordless telephone without "digital security", an insecure PBX, etc. The telephone network also offers other mischief opportunites such as call forwarding, voice mail, conference bridges, calling cards, third-party billing, collect calls and more.
Can people abuse the phone system? yes, of course it can, but the criteria for response are much higher, and in general the nature of the network (low concurrent session limit, point to point, voice only) as it is exposed to most people limits the damage that can be casually incurred.
There is a difference between crimes against the telephone system and crimes using telephones. The Department of Justice estimates Telemarketing fraud is a $40 Billion a year problem. But telemarketing fraud doesn't necessarily reflect a security vulnerability in the telephone system per se. Or at least not a security vulnerability that can be solved solely by the telephone system.