Don’t say we didn’t warn you: At some point in the next decade, there will be a “devastating attack” on the Internet or power grid.

That scenario was deemed most plausible by 1,300 technology experts and scholars in a survey released Jan. 9 by the Pew Internet ‘ American Life Project. Other predictions that drew the most agreement:

* We’ll be watched more closely by government and businesses through computing devices embedded in clothes, appliances, cars and phones.

* Most students will spend part of their day in “virtual classes,” grouped online with others who share their abilities and interests.

* And the boundaries between work and leisure will be blurred – in other words, expect to hear from your boss anytime, anywhere.

Although the Internet was technically born in 1969 as a plaything of computer scientists, it only became accessible to the mainstream a decade ago. Since then, it has insinuated itself in our daily lives. The handwritten letter has become quaint, millions of young music lovers have grown accustomed to free music (even if it’s illegal), and more than a few marriages have been forged from dates hatched online.

So what’s coming in the next 10 years?

Pew, along with Elon University in North Carolina, sought the opinions of people – both in the United States and abroad – who know the Internet intimately or think about it a lot. About half of them were Internet pioneers, having been online before 1993. One-third were from academia, another third were from tech companies or consulting firms and the rest worked for non-profit organizations, publications or the government.

Of the experts surveyed by Pew in the fall, 66 percent agreed that the Internet or power grid would be successfully attacked. Only 18 percent disagreed or challenged the prediction.

Former CIA Director Robert Gates, speaking at a terrorism conference last month, said cyberterrorism could be the most potent weapon of mass destruction and could cripple the U.S. economy.

“When a teenage hacker in the Philippines can wreak $10 billion in damage to the U.S. economy by implanting a virus, imagine what a sophisticated, well-funded effort to attack the computer base of our economy could accomplish,” he said.

The survey let people define what would constitute a “devastating” attack – would it mean millions of people having to forgo e-mail, instant messaging and Web surfing for a few hours, or would it mean human casualties?

“If we include economic devastation, it’s inevitable that we’ll see a number of companies and industries upended,” wrote Alexandra Samuel, a writer and consultant and author of a dissertation at Harvard University about politically motivated hacking.

“If we mean devastating in the sense of directly causing loss of life or injury, it’s much harder to predict.”

Intensified surveillance by government or business, and more arrests as a result, was foreseen by 59 percent of the experts. Some said they would welcome that development; others seemed to dread it.

“There will be greater surveillance, probably; greater arrests, maybe. But this is a chilling prospect overall,” wrote J. Scott Marcus, the senior adviser for Internet technology at the Federal Communications Commission.

Although many people have been predicting that the Internet would transform schools, it has yet to become much more than a research tool. Nevertheless, 57 percent agreed that most students by 2014 will receive some of their knowledge through videoconferencing or online chats typed out on a keyboard – otherwise known as “distance learning.”

The notion that the Internet will alter family life through home schooling and telecommuting drew agreement from 56 percent of the experts.

Harry Jenkins, a professor of literature and comparative media studies at Massachusetts Institute of Technology, wrote that people are already sensing the changes.

“For the most part,” he wrote, “they are very nervous about a world where it is impossible to escape the office and where they face growing competition for their children’s attention.”