Related to beer muscles where the internet is substituted for alcohol.
Can also take the form of “message board muscles”
When someone becomes "tough" and "combative" in an email, but never in person, or on the phone. A false show of digital power and might. A manifestation of their own sense of righteous indignation.
Ninja 1 in an email format: "I asked you for that report last week you never responded, I'm losing confidence in you and your firm & will take my business else where."
Ninja 1 in a phone conversation: "Hey buddy, I know you have been busy, any chance of getting that report any time this week? No rush!"