Piggybacking on someone else's wireless internet connection can be an offence under the Communications Act.
Scotland Yard said that when questioned the man said that he was using the unsecured wireless internet connection of a nearby house. He was arrested and bailed until 11th October.
The case was passed on to the Computer Crime Unit (CCU). "This arrest should act as a warning to anyone who thinks it is acceptable to illegally use other people's broadband connections," said Detective Constable Mark Roberts of the CCU. "Computer users need to be aware that this is unlawful and police will investigate any violation we become aware of."
The 39-year-old man could be charged under the Communications Act for dishonestly obtaining communications services. The Act says: "A person who (a) dishonestly obtains an electronic communications service, and (b) does so with intent to avoid payment of a charge applicable to the provision of that service, is guilty of an offence."
The CCU said that the man could also be charged under the Computer Misuse Act, though Struan Robertson, a technology lawyer with Pinsent Masons, said it is not clear how that law could be used to charge the man.
"The Computer Misuse Act is probably not relevant if someone is only taking advantage of an unsecured wireless network," he said. "A prosecutor would have to convince a court that a wireless router is itself a computer under that Act. It is far easier to justify a charge under the Communications Act for Wi-Fi leeching."
The Computer Misuse Act states that a person is guilty of an offence if "he causes a computer to perform any function with intent to secure access to any program or data held in any computer".
Many people leave their wireless networks unsecured, but to use that connection without permission is an offence. Two people were arrested earlier this year in Worcestershire in unrelated incidents for using wireless connections. Neither was charged.
There has only been one UK conviction for using wireless networks without permission. In 2005 Gregory Staszkiewicz was fined £500 and sentenced to 12 months' conditional discharge in London's Isleworth Crown Court.
Police have in the past advised users to consult with their internet service provider on how to secure their wireless internet networks.
