Google is tightening its famously open attitude towards free speech issues among its workers and telling them to stop discussing politics at work.

New "community guidelines" warns workers they will be held responsible for "disruptive" conversations.

"While sharing information and ideas with colleagues helps build community, disrupting the workday to have a raging debate over politics or the latest news story does not," the posting on the new policy states.  "Our primary responsibility is to do the work we've each been hired to do."

Google's founders proudly claimed that the now-former open culture helped produce the innovations that have revolutionized the tech landscape over the years.  But freedom of speech has had its consequences.  At least two engineers have claimed they were fired for expressing what they say were "conservative" opinions, although the company denies it.  And others have used internal char boards to rally co-workers against some controversial Google projects, pushing the company to end work on a censored search engine for the Chinese market and an artificial-intelligence contract for the US military.

"I think it's specifically intended to silence dissent," said Google engineer Irene Knapp, "This is the end of the important parts of Google's open culture.

"Ultimately, business interests will always win out over ethics in terms of what we’re allowed to say," she added.