Variations of the phrases were tweeted: "Enough, I'm tired of Murillo Karam," or "If you are tired, why don't you resign?".
Other people used it to vent their frustrations, protesting "Enough, I'm tired of living in a narco-state" or "Enough, I'm tired of corrupt politicians".
The missing students from a teacher training college in Ayotzinapa in Guerrero state had travelled to nearby Iguala to protest against what they said were discriminatory hiring practices, and to collect funds for their college.
But they went missing after clashes with the police.
More than 70 people have been arrested in connection with the disappearances, including the Mayor of Iguala, Jose Luis Abarca, and his wife, Maria de los Angeles Pineda, who were detained in Mexico City last Tuesday.