A cop resigned after admitting he wrote 'f------ pig' on his own McDonald's coffee cup, and it's the latest sign that fast food is getting caught in the fray of viral social issues

· Viral stories of discrimination in fast-food chains have become common in recent years. 
· In some cases, these viral stories can create company-wide change and spark a national conversation, as in the case when two black men were arrested at a Philadelphia Starbucks in 2018. 
· In other instances, hoaxes go viral,...