Wednesday's Senate hearing about protecting kids on social media focused on regulating yesterday's and today's technology — but lawmakers failed to grill executives on the rise of AI and the new problems it is generating.

Why it matters: The hearing, like those that preceded it, looked for solutions to longstanding problems — failures in content moderation, age verification, protection of teens' mental health and enforcement of laws against child sexual abuse material (CSAM) — but the tech industry keeps inventing new services that get put to bad use.

What's happening: Members of the Senate Judiciary Committee spent close to four hours grilling Meta CEO Mark Zuckerberg and his counterparts from TikTok, X, Snap and Discord on the sexual exploitation of children on their respective platforms.

• Senators used the hearing to try and win commitments on specific bills aimed at reducing social media harms to minors.
• But this latest in a long line of "protect the children" hearings in Congress had many legislators admitting their bipartisan campaign has so far been fruitless.

Between the lines: AI-based techniques power most of the filters and screens that Meta and other giant platforms use to proactively identify and remove CSAM material.

• The latest AI image generators, video engines and chatbots pose new challenges for parents and young users.

Yes, but: Aside from a brief mention by X CEO Linda Yaccarino, AI barely came up in the testimony.

Of note: A trove of 2021 Meta emails released before the hearing shows Zuckerberg and others at Meta were focused on how user safety concerns might play out in the company's plan to build the metaverse.

• In one email to Zuckerberg, Meta president of global affairs Nick Clegg called additional investments in the company's "external narrative of well-being" an "opportunity to be proactive for the metaverse."

Be smart: The hearing unfolded in the shadow of X's response to the circulation of sexually explicit AI-generated images of Taylor Swift.

• Those images were viewed millions of times, and X blocked users from searching for the singer's name for a period.
• "Someone as powerful as her, someone as strong as her, was impacted by Big Tech's negligence," Arielle Geismar, a team member of Design It For Us, said at a press conference by the activist group after the hearing. "As a young woman, I am horrified by the potential this could happen to me."

State of play: Zuckerberg played defense and tangled with lawmakers more than he had in some past appearances on Capitol Hill.

• When Sen. Marsha Blackburn (R-Tenn.) said Meta was trying to become "the premier sex trafficking platform," Zuckerberg interrupted to call that "ridiculous."
• But when Sen. Josh Hawley (R-Mo.) demanded Zuckerberg deliver a personal apology to families who filled the seats behind him, the CEO stood up, turned around and did just that.