The BBC's Watchdog programme claims to have exposed security weaknesses in many of the UK's wireless hotspots.
The consumer affairs show managed to hack into several accounts and send and receive emails using sophisticated but readily available snooping tools, and a coffee shop Wi-Fi connection.
The researchers penetrated the accounts of two audience members and Rav Wilding, an ex-policeman and current Crimewatch presenter. The programme identified hotspots operated by BT Openzone, The Cloud and T-Mobile as being at risk.
Tom Illube, chief executive at internet security firm Garlik, appeared on the show and urged people to use wireless hotspots with caution. He recommended the use of a virtual private network (VPN), but acknowledged that this might be too technical for most users.
The hotspot providers agreed that people should embrace such tools, and made a number of recommendations.
"We constantly review our approach to security and there will now be a direct link to security guidance from the BT Openzone landing page," said BT. "We are also reviewing our proactive approach to providing secure and user-friendly authentication."
The Cloud added: "Our security information, accessible via our web site and landing page, recommends the use of VPN technology. However we do recognise that they are not currently user friendly, especially for consumers."
Finally, T-Mobile said: "We have revised the wording on the hotspot landing page to emphasise the use of a VPN connection for optimal security."
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