BRUSSELS (Reuters) -Meta Platforms was told by EU tech regulators on Friday to provide more details on measures taken to tackle child sexual abuse material on its photo and video sharing app Instagram by Dec. 22 or risk a formal investigation under new EU online content rules. The European Commission in October sent a first request for information on measures taken to counter the spread of terrorist and violent content, and a second last month on measures to protect minors. "Information is also requested about Instagram's recommender system and amplification of potentially harmful content," the European Commission said in a statement on its latest query.