Unorganized individuals from twitter contacting your employer isn't harassment. If it is the implications would be scary the other way around: would you punish someone who pointed out a problem that happened to become popular on a social network?
That's not how cancelling works, except maybe in the case of celebrities. When you are canceled, no one calls and has a polite chat with your employer. They call and threaten your employer with arson. They find where you live and vandalize your home. It's harassment. It's illegal.