Salesforce.com customers were abuzz on Twitter Thursday morning as the result of what they described as a North American outage of the cloud computing service.

Salesforce.com's own Twitter account did not discuss the outage initially. Customers initially reported that the trust.salesforce.com service monitoring site was down and that when it resurfaced that it was showing all green lights despite the apparent outage of Salesforce.com software instances, which go by names such as NA5 and NA6. But others said the recovered Trust site did describe a "service disruption" lasting 21 minutes.

One customer wrote to Network World saying: "Just thought to let you guys know that Salesforce.com is having a major outage right now!! It is almost completely inaccessible, which means zero productivity for their customers, like me!!!"

Tweeter Morseworks wrote: "Salesforce.com's reliability is helping the competition and hurting the argument for SAAS."

Certified Salesforce.com admin Mikegerholdt tweeted: "So coming in to work and having #Salesforce go down is like waking up and being set on fire."

Meanwhile, other customers on Twitter expressed relief that the outage didn't last long, with one noting that you shouldn't look down on cloud computing because of the incident since local servers go down too.