Major US Internet companies are urging the British government to reconsider a plan to make telecommunications firms help spies hack into computers and phones.
The draft Investigatory Powers Bill would require telecoms companies to keep records of customers' Web histories for up to a year, and to help security services gain access to suspects' electronic devices.
In a submission to British lawmakers today, Facebook, Google, Microsoft, Twitter and Yahoo said that "to the extent this could involve the introduction of risks or vulnerabilities into products or services, it would be a very dangerous precedent to set."
They urged the government to reconsider, and warned against changes that would weaken online encryption, which they called a "fundamental security tool." The government says it will set out final proposals in the spring.