A riot cop here is a riot cop there

Can someone tell me why riot police all around the world now look like Darth Vader, with all black uniforms and nasty looking helmets? This picture is from Ukraine:

[Picture borrowed from http://www.spiegel.de/international/europe/ukraine-protests-kiev-makes-u-turn-on-eu-association-deal-a-938933.html]

Are they trying to counter the Black Bloc by trying to look like what they think the Black Bloc looks like?