Everytime protests against a countrys government start everyone is usually calling for a "peaceful" resolution, but what i recall from recent memory is that the peaceful protests in both Ukraine and Lybia didn't achieve anything, the only reason they succeeded was because it got violent, at least in the case of Ukraine.
But has any peaceful protest actually achieved the overthrown of their respective government?
Yes, the revolution of 1989-91 in several Soviet Bloc countries were mostly peaceful on the protester's side and resulted in bringing down Communist parties in said countries.
Moscow 1991 and Prague 1989 are two examples.