The act of using social media to communicate subliminal messages or take "shots" at a person you clearly have a problem or issue with by making indirect statements and comments on the Internet. You have no courage or "balls" to call them on the phone and speak directly, email them privately or sit down for a one on one in resolving the issue.
Sarah, the ex-girlfriend behaviors are consistent with a internet coward as she obviously has an issue with her ex's new fiancée being around her children based on her numerous social media posts of 'Wicked Stepparents'.

During the morning departmental meeting, our two co-workers disagreed about the next steps to take in finalizing our company project. This evening, worker #1 is behaving like a internet coward and has made several status post on Facebook clearly directed to worker #2 in subliminal messages.
by Satiresr March 20, 2015
Get the Internet Coward mug.