Skype has joined Facebook and Hotmail on IT department blacklists as organisations limit avenues for information leaks, an Integ survey found.
Four in 10 of the 233 respondents surveyed at the recent AusCERT conference said they were blocking the popular internet telephone service, while a third blocked Facebook and Hotmail.
Hosted audio conferencing was also blocked by 13 percent of those surveyed.
It found organisations were finding other, more easily managed ways to communicate.
Nearly half said they provided workers with an internal instant messaging tool, half provided collaboration tools such as Microsoft Sharepoint, and more than a quarter had their own blogging software.
"Organisations are keen to keep the elements of [popular social networking] tools that have business use in their internal environments," said Integ chief Ian Poole.