In a San Francisco federal court, the Communication Workers of America union recently expanded the scope of the class action suit they filed last December against some of the country’s largest employers — a diverse list of companies that included Amazon, T-Mobile, Capital One, and Enterprise Rent-a-Car — accused of deliberately targeting their Facebook ads to exclude older workers. A ProPublica investigation shows that IBM has quietly pushed out upwards of 20,000 aging workers over the past five years. And, for all that has been written about the woeful lack of diversity and the “bro culture” that prevail in the tech industry, Silicon Valley’s 150 biggest tech companies have faced more accusations of age bias over the past decade than racial or gender bias.