Internet messages started with a crash 40 years ago today, and life hasn't been the same since. “We transmitted the ‘L’ … and the ‘O’ — and then the other computer crashed,” says UCLA's Leonard Kleinrock, who helped send that first message on the university's campus on Oct. 29, 1969. He was trying to type the word "login."

"We knew and we didn't know that it was going to be a big deal," he says..

Kleinrock, celebrated at a scholarly symposium at UCLA today, built the Internet's method of breaking messages into "packets" and shipping them across networks. He was awarded the National Medal of Science last year.

The 1969 crash wasn't due to the "LO" message itself, but a memory problem with the receiving computer, Kleinrock says. "I actually took part later in the first denial-of-service attack on the Internet as well. We sent the first spammer in 1984 so many messages, complaining, that we shut him down."

Early Internet (then ARPANET) users operated on an honor system, Kleinrock says, which has led to problems later. "If we had to do it over again, we would have built more controls into the Internet to keep the 'dark side' of things out. But it has been an incredible time."

By Dan Vergano