(December 3, 2020, 1:23 PM EST) -- SAN FRANCISCO — Pinterest Inc.’s board of directors and certain of the company’s senior executives breached their fiduciary duty by aiding a culture of illegal racial and sexual discrimination in the workplace, an investor alleges in a Nov. 30 shareholder derivative complaint filed in California federal court (The Employees’ Retirement System of Rhode Island v. Benjamin Silbermann, et al., No. 20-8438, N.D. Calif.)....