Chief prosecutor Valeriu Zubco dropped the charges on November 11 against Morari and three others, including Gabriel Stati, the son of Moldova's richest businessman.
Morari, 25, has admitted using Twitter to call on friends and others to demonstrate after the controversial April 5 parliamentary elections, but said she never intended for violence to occur and is not responsible for those actions.
The fierce protests against the conduct and result of the elections led the mass demonstrations to be called the "Twitter Revolution."
Moldova's Communist Party won the April elections, but it was forced to hold new elections by the pro-Western opposition, which finished first in the second poll of the year in July.
Morari, who has a blog on RFE/RL's Moldovan Service website, spent several weeks under house arrest after she was charged.