Websense, a supplier of Internet content management software, has warned that many users will be tempted to download film trailers at work taking advantage of corporate Lan connections that offer greater bandwidth than domestic dial-up connections.
The company has highlighted a 400% increase in the number of streaming media sites in the past 12 months, with most of them containing popular film trailers.
According to WordSpot, an Internet keyword detection service, "Star Wars" and "Spiderman" now appear in the top 30% of phrases used most often in search engines. Other potential blockbusters are due out this summer, adding to the potential problems for network managers.
The appearance of peer-to-peer sites that allow users to share video and music files could burden an already overloaded network.
Geoff Haggart, Websense Europe vice-president, said just four staff members downloading a 4Mb movie trailer could seriously slow a corporate Lan.
Cisco chief executive John Chambers summed up the problem at the recent Networld + Interop trade show in the US, when he said streamed video was a "bandwidth hog" with a half-hour video being the equivalent to a year-and-a-half of e-mail.
Websense says an increasing number of organisations are now choosing either to block or manage streaming media by allocating to employees specific capacity or less times when the network is quiet.
One of the latest large companies to adopt such a solution is construction company Carillion. Local authorities are also said to be taking the video-streaming problem seriously, with Lewisham and Barnet councils in London among the ones clamping down.