A computer-implemented method, system, and/or computer program mediates a co-editing session for a document. After establishing a co-editing session for a first user and a second user to co-edit a document, a first modification of the document is received from the first user. A second modification of the document, which eliminates the first modification, is subsequently received from the second user. In response to a quantity of subsequent modifications, after the first and second modifications, exceeding a predetermined value, an action is initiated to prevent further modifications to the document.