The news: Ad verification firm DoubleVerify is threatening to sue advertising watchdog Check My Ads, stating the latter should “reasonably anticipate litigation” in a Monday letter.

• Check My Ads promoted an Adalytics report that claimed DoubleVerify allowed ads to be placed on websites known to host child sexual abuse material (CSAM) and failed to detect bot traffic. Check My Ads collaborated with Adalytics to raise awareness, making statements about the report that DoubleVerify believes constituted “defamation, tortious interference, and injurious falsehood.”
• Check My Ads said it will comply with legal obligations, but that it stands by its work.