Social-network users are hogging more computer-network bandwidth - from the cubicle next door.
A growing proportion of the capacity on corporate networks is being taken up by employees actively using social networking applications and file-sharing services, according to Palo Alto Networks, a US computer-security company that tracked network usage at more than 1600 customers between last April and November.
Active usage - referring to people who play, post and share rather than just passively watching a scrolling feed of posts on Facebook's site, for example - took up 28 per cent of total network bandwidth used on social sites.
That's a rise from 9 per cent in the preceding six months. Facebook applications took up 13 per cent of social bandwidth, about triple the previous period.
While active usage had risen, the percentage of total network bandwidth social and file-swapping sites took up had been steady at about 1 per cent, Palo Alto said. Some active social networking is sanctioned by bosses.
More companies were creating corporate Facebook applications and asking workers to attract customers and respond to queries on such sites as Facebook and the microblogging site Twitter, said Matt Keil, senior threat analyst at Palo Alto Networks.
Other traffic comes from tasks that are less likely to be work-related. More than 50 per cent of the companies measured had workers playing Zynga games on Facebook, using about 5 per cent of social-networking bandwidth.
Of those in the survey, 57 per cent had workers spending some time trading film clips and games on a site called Megaupload. Half had workers using FilesTube, a site that features some movies, said the report.
The problem for companies was more serious than employees using work time to watch movies, Keil said. Most of those file-sharing services sail straight through a company's firewall, making them useful to hackers.
Palo Alto tracks this because it sells advanced firewall appliances that let customers specify which applications and behaviours to scan for viruses and Trojans or block altogether.
For example, Keil said, the devices could be set to let marketing departments post on Facebook while all other users could merely view posts.
As part of that, Palo Alto measures what applications reside on customers' networks. It found 71 kinds of social networking apps and 65 flavours of browser-based file sharing.