If an HTML e-mail is sent on Yahoo!’s service, the word “mocha” is automatically changed to “espresso”, and the word “eval” becomes “review,” according to Reuters.
A spokeswoman for Yahoo! told Reuters that the reason for changing these words is that they are commands in the JavaScript programming language that can be used to create malicious programs.
A spokeswoman for rival Hotmail claimed that Microsoft’s free e-mail service blocks certain words which can be used by hackers but that it does not alter the contents of messages.
Interference with the contents of e-mail messages could raise privacy concerns.
Struan Robertson, editor of OUT-LAW.COM, said:
“If Yahoo!'s service is being operated from the US and its servers are based in the US, it is unlikely that any successful claim can be made against the company under European laws.
“However, if its UK operations were amending the content of e-mail messages, issues may arise under the Data Protection Act and the Regulation of Investigatory Powers Act. The contents of an e-mail are personal data. To make changes to the contents of an e-mail without giving notice to users that this will happen could amount to a breach of the Data Protection Act.
“There are unlikely to be many situations where harm is caused by Yahoo!'s practice, but it is feasible that, for example, someone failed to get a job as a result of the amendment to an e-mail. ‘Please call me when you have reviewuated my CV’ would not impress any employer. Also, the Regulation of Investigatory Powers Act creates an offence of unlawful interception of communications which can apply when e-mail messages are intercepted and amended without consent.”