Pro-union flyers appear in Starbucks headquarters as some corporate staff quietly support barista strikes

Starbucks' Seattle headquartersDavid Ryder/Getty ImagesThis week, baristas at unionized Starbucks stores launched their fourth strike in two years.Flyers supporting the strike have begun quietly appearing at the company's Seattle headquarters.Two corporate employees said HR urged staff to report if they see pro-union actions at work.Dozens of pro-union flyers have appeared around Starbucks headquarters since baristas at 65 stores launched a nationwide strike — and the company is on alert f