An ad by Sen. Elizabeth Warren's campaign that says Facebook has endorsed President Trump (before admitting the claim is a lie) is having its intended effect: raising tough questions about Facebook's policy of allowing politicians to make any claims they want.

Why it matters: Facebook has spent much of the last 2 years talking about its efforts to protect elections. But while Facebook is cracking down on foreign interference and deliberate voter suppression, it is giving political candidates carte blanche to distort and deceive.

Driving the news:

• Facebook has green-lighted an ad from President Trump that makes false claims about Joe Biden. (So have Twitter and YouTube.)
• Elizabeth Warren posted an advertisement saying falsely that Facebook and Mark Zuckerberg had endorsed Donald Trump. In the post, she quickly acknowledges that's not actually true, but says that by allowing falsehoods, Zuckerberg has "given Donald Trump free rein to lie on his platform — and then to pay Facebook gobs of money."

Facebook responded on Twitter Saturday that broadcast stations across the country aired this ad nearly 1,000 times, as required by law. "FCC doesn't want broadcast companies censoring candidates' speech," Facebook said. "We agree it's better to let voters — not companies — decide."

Yes, but: The broadcast networks operate under unique rules because they are using public airwaves. Businesses operating in nearly every other type of media can (and often do) set their own rules, including cable, internet and outdoor media.

History lesson: Every company or person who has ever been in charge of a platform, a message board, or a comments area knows that trolls are going to take any rule about acceptable content and stress-test it from a zillion directions.

• The problem here is what to do when those pushing the boundaries aren't everyday trolls, but rather the president of the United States and one of his leading challengers. 

Facebook, for its part, has invested a lot in creating a more systematic approach to evaluating content, clarifying its community standards, bringing in third-party fact checkers, and setting up an independent "Supreme Court" appeals board to provide a final say. (Facebook says it's focusing the fact checkers' limited time on memes and hoaxes, not politicians' words.)

Facebook argues it should take a nearly completely hands-off approach to what politicians say in their paid advertisements, and it's not alone — many critics, as well, don't want to see the social network set the boundaries of political speech. (See below for just what the social network is and isn't allowing.)

My thought bubble: As political ads inevitably keep testing Facebook's boundaries, the company's best solution may be to stop taking them altogether (as some transit agencies have, for example) — trading a modest revenue loss for the opportunity not to be blamed for swinging a second election in a row.

Facebook may be giving political figures free rein to make false claims, but that doesn't mean they can say anything.

What Facebook won't let politicians say:

• They can't misstate details about the voting process, such as when an election is taking place, the rules or how to vote.
• They can't include profanity, as Trump's campaign found out.
• They can't embed social media posts that have been flagged by a fact checker.
• While not held to standards on factual matters, they have to follow Facebook's other community standards, such as those on hate speech.

What politicians can say on Facebook:

• They can make just about any factual claim they want, including repeating verbatim a false claim that has already been labeled elsewhere as false. That means they can misstate their own record or that of an opponent.

Between the lines: Here's where it gets even messier. Politicians can take an already debunked claim and repeat it in their own ads. A regular user, meanwhile, can't take a false claim from a politician's ad and repeat the same words without violating Facebook's rules. They are, though, free to share that politician's ad.

The bottom line: Politicians still have a lot of room to mislead voters, especially when they can target different messages to different demographic groups.

Monday is the deadline for Amazon, Apple, Facebook and Google to respond to demands for information about their businesses from House investigators probing competition in the tech industry, Axios' Margaret Harding McGill reports.

The big picture: The House Judiciary antitrust subcommittee sought communications from company executives and answers to a slew of questions about market power and acquisitions.

Be smart: It's unlikely the firms will respond in full today, but lawmakers can issue subpoenas if they believe the companies aren't complying in a timely manner. And while the questions were posted publicly, there are no immediate plans to publicly share the responses.

• In addition to the big 4 firms, the lawmakers also sent inquiries to more than 80 companies seeking details about competition in the markets, and those responses are also due today, according to a person familiar with the investigation.

What's next: The antitrust subcommittee will hear from FTC commissioner Rohit Chopra and others Friday at its third hearing focused on online platforms, exploring data and privacy issues.

San Francisco legislators have a new idea to tackle all the new tech that roams around their streets: an Office of Emerging Technologies. As Axios' Kia Kokalitcheva reports, the new office would dole out approvals to startups and companies wishing to unleash new gadgets and services on the city.

Why it matters: San Francisco is home to many tech companies that aim to reshape urban life, but the city has often seemed ill-prepared to deal with them, whether by welcoming or regulating them.

The details: The office, established in a bill proposed last Tuesday by Board of Supervisors President Norman Yee with the support of City Administrator Naomi Kelly, would be housed in the Department of Public Works.

• Companies would have to get permission from the office before they can test any new products in San Francisco.
• The office would coordinate with various departments to assess the positive and negative effects a proposed product or service would create and issue an approval or denial.
• Ideally, it would also help companies better understand the city's relevant rules and regulations from the outset. Small startups with limited regulator experience have often struggled to do more than apply for basic business permits.

Be smart: Because it would be housed in the Public Works department, the office's jurisdiction would be limited to sidewalks, storefronts and the like. It's not clear if it could regulate, for example, ride-hailing services like Uber and Lyft or home-rental outfits like Airbnb.

• Rather, the office seems to be a response to the recent (unexpected) rapid rise of electric scooter rentals and the delivery robots some companies have tested in the last couple of years.
• Yee has in past expressed concerns over the danger they pose for vulnerable users of the city's sidewalks, like those with wheelchairs or senior citizens.

Go deeper: SF officials want to regulate cutting-edge tech. Would their plan stifle innovation?

On Tap

• India Mobile Congress takes place today through Wednesday in Delhi.

Trading Places

• As GeekWire reports, former Seattle Seahawks receiver Doug Baldwin is now a senior adviser of product concepts at Intellectual Ventures, Nathan Myhrvold's Bellevue, Wash.-based patent and invention company. 

ICYMI

• WeWork is said to be considering a bailout that would give control of the company to SoftBank. (Bloomberg)
• Visa, Mastercard, eBay and Stripe are joining PayPal in pulling out of Facebook's Libra project, ahead of release of the cryptocurrency foundation's charter, which is reportedly due to be finalized today. (Axios)
• California joined Oregon and New Hampshire in banning police from using facial recognition via their body cameras. (SF Chronicle)
• Activision Blizzard is reducing the suspension of a gamer who spoke out in favor of Hong Kong protesters and restoring his winnings. (Bloomberg)

When Hulu mixes up the captions for a "Golden Girls" episode with ones from "Buffy The Vampire Slayer," hilarity ensues.