That's bullshit. Write a "manifesto" about how senior executive compensations are to high, the company should be taken over by the employees and that private ownership of properties is a crime. That's the REAL leftist position. Then send that manifesto out to thousands of employees on the company's internal mailing list and see how long you last.
People fail to see the point... Yes, there are many "leftist" positions. The above is one of them. The point is that expressing that position on an internal mailing list most certainly puts your employment in jeopardy. It doesn't matter what the position is (abortion, drug legalization, gay weddings, military attacks on civilians, foreign relations, ...), what matter is where you express it.