There are Cossack Organizations in Ukraine.  However, they're not as prominent as they used to be (funding from Moscow dried up when Yanukovych became Prime Minister and thus the Cossacks could no longer afford  to pay their members  :D  ;D).

There are still some Cossacks operating but they tend to be criminals and highwayman,  http://ukrainianweek.com/Investigation/25749

there are numerous cases of men in 'Cossack Uniforms' who pretend to be traffic police and fine people for a living.