Twitter warns of possible overload during World Cup

Twitter is warning users that it could see more of the outages it has been suffering since last weekend, especially as the World Cup kicks into full gear.

Site engineers blame technical glitches for the recent problems on the popular social networking site, but say that even a recent doubling of capacity may not be enough to prevent shutdowns over the coming days.

"During the World Cup tournament --and particularly during big, closely-watched matches (such as (today's) match between England and the U.S.A.)-- we anticipate a significant surge in activity on Twitter," Twitter engineer Jean-Paul Cozzatti writes on the site.

"While we are making every effort to prepare for that surge, the whale may surface."

The whale refers to the image of a smiling, blissful cetacean being lifted by red birds that Twitter users see when the site experiences an outage. The image is accompanied by the words "Too many tweets! We'll try to lighten the load and have things back to normal soon."