Just as with anything on the Internet, there are certain kinds of street art that will fare better on social media than others. Judging from a recent Tumblr list on the most popular posts about street art, site-specific pieces, optical illusions, and text-based murals tend to catch fire with the public and go viral more than anything else. That's why December 2014 was such an interesting month for street art. Most of the murals that went up during Art Basel Miami Beach 2014 and Artesano Street Art Festival, an event held in the Dominican Republic, did not contain any of the qualities that make a work of street art go viral.

Instead, it seems like street artists decided to focus on the content of their art more than anything last month. Whereas murals in past months stood out for their larger-than-life size and muted colors, this month's pieces all seem to emphasize imagery. Some are highly detailed, displaying intricate line work and skillful draftsmanship in general. Just see the pieces by Alexis Diaz and Axel Void for example. Others are striking because of the entire image as a whole. Shepard FaireyCleon Peterson, and even Ludo's latest works feature thought-provoking, sometimes deeply political images. Slide down to see all of In These Streets: The Best Street Art From December 2014​.