On May 15, the FTC announced that it sent letters to businesses to help them comply with new requirements under the revised Children’s Online Privacy Protection Act (COPPA) rule. The letters went to 90 businesses whose online services or mobile applications appear to collect personal information from children under 13, as defined by the revised rule. The letters differ depending on whether the business is domestic or foreign, and whether the business collects images or sounds of children, or collects persistent identifiers.