I was in the communications industry in the early eighties shortly after the AT&T divestiture, and at that time it was piggybacking lines from Ma Bell under the "essential services" (sound familiar?) part of what I believe was the Sherman Act. The US Courts called it "equal access", but it required companies like the one I was with to dial # this or * that, anything but equal. It was always explained to our customers that dialing the "pound sign" first was a way to stick it to the man who's been digging in your pockets and your family's pockets for over a hundred years whether you liked it or not. It worked for a while, I was successful, my father made millions, and it was all good until slowly the smaller firms were gobbled up or forced out. Forty years later and the Bell companies are now once again the big dogs in town. Two of the biggest cellular service networks are AT&T and Verizon, former Bell companies. Century Link? Northwestern Bell back in the day.Never knew it was a pound sign until I went to China. It has always been hash here in Australia to my knowledge. of course we used to have pound as a currency which is £ so that is maybe why we called it hash. It would be interesting to hear what Europe and the UK call the # sign.
FYI, did you know that you can dial *67 on your cellphone before the phone number and it will come up "unknown" on almost all caller ID and cellphone carriers? Who wants a prank call, I'll show you.?.