"The thieves are educated and bright computer fanatics who know what they're doing," said Det Insp Bob Berger, who is co-ordinating a crackdown on memory-chip theft.
Memory chips, also known as RAM (random access memory), are essential for computers to operate. Burglars can sell stolen chips to small businesses looking for cheap upgrades, or to second-hand dealers. "It's safer than dealing drugs," says DI Berger. "One of the people we arrested had done pounds 500,000-worth of business between February 1994 and June 1995."
Bank holidays are popular times for thefts. Once inside offices, burglars can remain for hours, and sometimes remove the chips so tidily that the businesses do not realise their loss until the machines are restarted on the Tuesday.
This weekend burglars have an added incentive to strike. Modern PCs require at least 4 megabytes of RAM to function, but Microsoft's new Windows 95 operating system requires at least 8Mb, and some users have installed 16Mb or more, worth hundreds of pounds.
Nor are the thieves likely to be put off by the fear of prosecution. DI Berger led Operation Eastside, which in July raided 44 addresses in London, Leicester and Swindon after six months' investigation. A total of 29 people were arrested but none have yet been charged. Furthermore, they could only be charged with burglary, which typically attracts a sentence of 18 months or less.
"The maximum sentence for burglary is 18 years, but sometimes these people just get off with community service," says one police source. "The courts have clearly displayed the low priority they put on this crime."