Excellent trend: Men are taking pictures of their penises in socks and posting them on the internet with the hashtag #cockinasock to raise awareness for testicular cancer.
If you don't have a cock, a sock, or you're just not down with taking pictures of your penis in a sock, then you can help by donating to cancer research at this page.
Basically, as demonstrated below, it is probably the best hashtag to exist in the history of the hashtag and human existence.
And the best for last:
UPDATE 2: Apparently Instagram has unblocked the #cockinasock hashtag AKA more proof that God is real and a gay man or a straight woman. Amen.