BlackBerry outages are rare, but when they do hit, like one did Monday that wiped out service across United States and Canada, subscribers who have become addicted to the smart phones are quick to unleash their fury.

"I'm mad – it's enough already," said a frustrated Stuart Gold, who said he gets 1,000 emails a day as director of field marketing for web analytics company Omniture Inc. and can't afford the downtime.

Gold, who worked most of Monday on a laptop while traveling, plans to ask his company to buy him a backup smart phone from a rival like Palm Inc., which makes the Treo, in case BlackBerry service goes on the blink again.

"I don't know what happened, I don't care what happened. They need to save their excuses for someone who cares," Gold said.

It was not immediately clear late Monday what caused the outage – the second widespread disruption in less than a year. Some users reported being able to access their service normally.

Research in Motion Ltd., the Waterloo, Ontario-based company that makes the ubiquitous mobile device, said late Monday that customers "experienced intermittent delays" beginning around 3:30 p.m. EST, but data service was restored about three hours later. The company said voice and text messaging services were not affected.

"No messages were lost and message queues began to be cleared after normal service levels were restored,' RIM said, apologizing to customers for the inconvenience.

The company did not say how many customers were affected, though officials with AT&T Inc. and Verizon Wireless said RIM told them the outage hit customers of all wireless carriers.

Bell Canada spokesman Jason Laszlo said the majority of its BlackBerry customers were affected.

RIM has 12 million subscribers worldwide and has deals with scores of wireless carriers to offer the BlackBerry service around the world.

On Monday, users described frantic moments of tapping away at disabled machines before realizing an outage had zapped their service.

"Everyone's in crisis because they're all picking away at their BlackBerrys and nothing's happening," Garth Turner, a member of the Canadian Parliament, said during a caucus meeting. "It's almost like cutting the phone cables or a total collapse in telegraph lines a century ago. It just isolates people in a way that's quite phenomenal."

The BlackBerry service, which lets users check email and access other data services on their handheld devices, has become a lifeline for many business executives and is increasingly popular among consumers with models like the BlackBerry Pearl.

Outages have been rare in the device's nine-year history.

The last major BlackBerry outage happened last April, when a minor software upgrade crashed the system, triggering complaints from always-on users all the way up to the White House and Canada's Parliament. A smaller disruption happened in September, when a software glitch stanched the flow of emails to subscribers.

The previous BlackBerry outages have prompted angry backlashes against RIM because of the company's lengthy silences about what caused them and the cryptic and jargon-laden explanations that eventually emerge.

RIM waited two days after the April outage before telling customers what happened.

The last major failures were nearly two years before that. The company angered users by waiting hours before confirming the problem, then issuing a confusing technological description of what happened.