look up any word, like rimming:
A shareknight is someone who shares pictures on facebook or other social media drawing attention to whatever tragedy is in the news at the time, supposedly because they care, but mostly because they want people to know they care.
"Did you see that picture about tragedy x that John shared last night."
"Yeah, that dude is such a shareknight. I wish he'd stop wasting my precious bandwidth."
"When did sharing that stuff accomplish anything anyway?"
by Kaasbaviaan April 16, 2013