"We are building a tool that is constantly keeping tabs on us," said Brad Templeton, chairman of the Electronic Frontier Foundation, a US self-appointed privacy watchdog.
Speaking at the Presence and Instant Messaging Conference in Boston last week, Templeton said his chief concerns are the logging of chat conversations, their lack of encryption and the potential for hackers to use them to track where you go.
Also brewing are issues such as how and when governmental entities, such as law enforcement agencies and the courts, can obtain IM (instant messaging) transcripts, usage information or other data.
"Most people don't care about security and privacy until they've lost it," says Lenny Foner of the Massachusetts Institute of Technology's Media Lab. "Let's not build in Big Brother."
A lot of us are already blithely chatting away. Market researchers at research group IDC estimate people sent 900 million instant messages on a typical day last year and will send about 7 billion a day by 2004.
According to a February report by Jupiter Media Metrix, Microsoft's MSN Messenger has 29.5 million members in 12 countries, AOL Instant Messenger has 29.1 million members and Yahoo Messenger has around 11 million.
The three leading instant messaging services all dispute claims that their systems lack security, and each says it does not log customers' conversations or keep tabs on where they go.
IM security issues take a new twist on wireless mobile devices, conference attendees agreed. Because mobile phones will soon be able to pinpoint where you are physically, that information will be valuable to advertisers. They may send an IM to lure you, for example, to a nearby coffee shop by including a digital coupon for $1 off a frothy one.