(CBS) — It’s been a high-tech nightmare in the financial, and airline industries today because of separate glitches.

Trading was halted at the New York Stock Exchange for 3 1/2 hours after what has been described as an “internal problem.” Trading later resumed, with sizeable losses.

This was followed by temporary trouble accessing the Wall Street Journal’s website, and a flood of conspiracy theories on social media about a coordinated hack attack.

But before all this happened, United Airlines grounded flights across the country for nearly two hours, because of what they call a “router issue.”

CBS 2’s Mike Parker reports in every one of these incidents, it was computer technology breakdowns, not a hostile set of attacks. But one local expert says more of those are sure to come and we should be ready.

With the outages at the NYSE and United Airlines, some people wonder if this brave but vulnerable new world of computers could be open to a much bigger failure: a major enemy hack attack.

Jim Aman is an associate professor emeritus from St. Xavier University.

“I think it is distinctly possible,” Aman said. “I know where the vulnerabilities are and I know people who can get into the systems.”

Aman worries about the nationwide electric power grid controlled by computers.

And what about a blackout in the nation’s banking system?

“We always live in a dream world,” Aman said. “We live in hope, don’t we?”?”

But Chicagoan John Strickland is growingly dubious about the interconnected world, “Cause anybody can hack into your computer.”

“It’s not a question of “if” you will be breached,” Aman said. “It’s when.”

Although cyber expert Jim Aman is pessimistic about our internet safety and future, he did admit today, he banks online.