He was arrested in December 2015 as a wave of anti-government protests in the Oromia region was gathering momentum.
The authorities objected to several posts including one in which he said the government used force against the people instead of peaceful discussion.
Ethiopia has been criticised for using anti-terror laws to silence any disagreement.
More than six hundred people died in clashes between security forces and the demonstrators as the authorities tried to deal with the unrest, according to the state-affiliated Human Rights Commission.
