when popular websites like Quora, foursquare and Reddit were left staggering or totally knocked out because of server problems in the Amazon datacenter that handles the company's Web hosting services.

While by 4 p.m. ET to some sites such as Foursquare, Quora was still disabled and Reddit was still being affected.

"Reddit is in 'emergency read-only mode' right now because Amazon is experiencing a degradation," the company noted on its site. "They are working on it, but we are still waiting for them to get to our volumes. You won't be able to log in. We're sorry and will fix the site as soon as we can."

According to AlertSite, a Web performance management company, between 6 a.m. and 1 p.m. ET Thursday, one portion of the Reddit site took more than 60 seconds to load, only to return an error message. Foursquare's homepage had 84.44% availability between 8:15 a.m. and noon, also returning error messages explaining the downtime and slowness.

At 5:16 a.m. ET Thursday, site administrators reported that they were dealing with connectivity issues impacting Amazon's Relational Database Service, which is used to manage a database, across multiple zones in the Eastern United States.