Twitter's most used hashtags of 2015 are depressingly heavy

Forget throw back Thursdays and winky emoji - Twitter's review of 2015's biggest hashtags, retweets and trends reflects the major events of the year with saddening poignancy.

 #JeSuisCharlie and #JeSuisParis were the most used hashtags of the year, as the world rallied behind the nation of France in the wake of the terrorist attack on the Paris offices of satirical magazine Charlie Hebdo. Ten months later, and the nation's capital was once again on the lips and screens of the world, as #PrayForParis became another of the site's most-shared sentiments of the year.

The year's second most-discussed 'moment' was encapsulated by the #BlackLivesMatter tag - a movement that picked up some nine million tweets in 2015 as the US responded to events in Ferguson, Charleston, the Baltimore protests, calling for recognition and action against police brutality against black US citizens.

Drawing further contrast to 2014's year of World Cup, Winter Olympics and Oscar hashtags, 2015's other most discussed events all carried a significant weight of social impact.

#HomeToVote and #LoveWins signified international support for and celebration of marriage equality in both the US and Ireland, while #RefugeesWelcome became a top trending hashtag in the wake of Middle Eastern unrest, as many began to seek refuge in European nations.

For more on Twitter's review of 2015, head here.

And no, we don't know why December doesn't count either.