hashtag activism 

The kind of activism undertaken when you "do something" about a problem by tweeting or posting links to Facebook, without any intent of ever actually doing something. Nothing more than a nonsense feelgood gesture so that one can say they "did something about" whatever trendy cause they're pretending to care about. Usually only lasts a week or two before the cause is completely forgotten (i.e. it stops being cool to forward/retweet on the subject).

I forwarded a video about some unspeakable atrocities in a country I didn't know existed until I watched the video. My hashtag activism is going to accomplish something!

hashtag activism by CJ.MK.87 June 17, 2012

hashtag activism 

Hashtag activism is the act of fighting for or supporting a cause that people are advocating through social media like Facebook, Twitter, Google+ and other networking websites

many people used hashtag activism to bring forth the Black Lives matter movement.

hashtag activism by sickwititcudi April 5, 2017