Let’s conduct an experiment. I blindfold you and direct you to walk 20 paces forward. If you exceed that limit and walk 21 paces you will fall into an open manhole. But that’s not going to happen, right? Because I told you not to walk more than 20 paces. I even told you what would happen if you walked that one additional pace. Just to be safe, I told you twice. We can all agree, I think, that if you walk 21 paces anyway and fall into the open manhole, then it’s your own goddamn fault.

Let’s change the experiment slightly. Now if you walk into the manhole, I get paid $100. I’ll still warn you about that manhole 21 paces ahead, but maybe instead of telling you twice, I’ll tell you only once.

Now let’s change the experiment again. Instead of directing just you to walk 20 paces forward, I direct millions of people, all at the same time. I’ll still warn these millions about that manhole 21 paces ahead, even though I stand to gain $100 for each person who falls into it. I’m not a monster, OK?

But maybe I’ll warn these millions in a letter containing lots of other data. I’ll tell myself this is more efficient, and try not to dwell on the likelihood that most people will toss my letter into the trash unread. In that same letter, and perhaps also in some how-to-walk-blindfolded instruction book these millions are never going to look at (because they know how to walk blindfolded, for Pete’s sake; it isn’t that complicated!),I’ll let my subjects know that they have one additional safeguard. They can stop at any time, ask how many steps they’ve taken, and I will tell them. I really will! If, on the other hand, they don’t take the trouble to ask (probably because, in the midst of their busy lives, they never read my statements about the dangers and how to avoid them), and if they then fall down the manhole—each casualty making me $100 richer than the last—then it’s still their own goddamn fault. Isn’t it? Isn’t it?

In the first version of this experiment, I am a scientist. In the second, I am a fallible human being. In the third, I am a cell phone company.

On Oct. 14, the Federal Communications Commission proposed a rule compelling mobile service providers to shout “Stop!” whenever a customer is about to walk into a manhole. More literally, the rule would require cell phone carriers to alert customers on the verge of exceeding monthly usage limits and incurring overage charges. These would be in the form of text or voice alerts on the phone itself, not unlike the conspicuous emergency message you’re liable to receive if you’re late paying your cell phone bill. Mobile carriers would similarly have to alert consumers if they were about to incur roaming charges. They would also have to give customers better and more conspicuous tools to keep track of how close they were to reaching a usage limit, and perhaps provide them with a tool to cap usage automatically so that exceeding usage limits—walking into a manhole—became impossible.

This regulation, if made final after the required 60-day comment period, would be a big improvement over the status quo. Even so, it doesn’t go far enough.

If you doubt that incurring an overage charge on your cell phone bill can be like walking into a manhole, consider the case of Robert St. Germain, who accompanied FCC chairman Julius Genachowski on Oct. 13 when Genachowski gave a speech about “cell phone bill shock” at the Center for American Progress. As Megan Woolhouse reported in the April 30 Boston Globe, St. Germain incurred nearly $18,000 in overage charges from Verizon because his son Bryan didn’t know the family plan’s two-year unlimited-data premium, a come-on to lure new subscribers, had expired when his father renewed with Verizon. Robert had a poky dialup connection (this was 2006), so Bryan used his cell phone to connect his laptop to the Internet and then downloaded a lot of songs. Unbeknownst to father and son, Verizon was charging by the kilobyte. In no time, Bryan had racked up $17,833 in charges. After the Globe story appeared, an indignant Verizon spokesman wrote in that Robert had been notified of the terms “in brochures, during the purchase process, in our customer agreements and again through confirmation letters.” St. Germain could have looked up his coverage limits on the MyVerizon Web page (let’s have a show of hands, Verizon users: Have you ever been to this site?) or he could have dialed #BAL for balance information, #DATA for data usage, or #MIN for available minutes. Or he could have flown around the world really fast like Christopher Reeve did in Superman *to go back in time and save Lois Lane from the avalanche that just killed her. (OK, I made that last one up.)

What’s stunning about St. Germain’s case is how weirdly resistant Verizon was to cutting him any slack. Its best offer was to halve the bill (a mere $8,600!). It forgave the debt only after the Globe story brought the company a truckload of bad publicity (and unwanted attention from the FCC). “Bill shock is a very high margin item in the industry,” St. Germain explained at the Center for American Progress. “They make a lot of money from it.” St. Germain’s bill wasn’t even the most outrageous one spotlighted at the event. That prize goes to Kerfye Pierre, a federal employee for the Federal Emergency Management Agency, who, while in Haiti after the earthquake, unwittingly ran up $35,000 in charges from T-Mobile for data downloads and text messages. According to a new FCC white paper, the agency received 764 bill-shock complaints during the first six months of this year. Sixty-seven percent concerned bills of $100 or more; 20 percent concerned $1,000 or more; and 1 percent (eight of the 764) concerned charges of $10,000 or more. The largest surprise charge was $68,505. The Government Accountability Office reported in Nov. 2009 that 34 percent of all wireless phone customers reported receiving “unexpected charges” on their bills. That sounds low to me. (According to the report, 31 percent “had difficulty understanding their bill at least some of the time.” I know that’s low.)

Why do I say the FCC’s proposed rule doesn’t go far enough? Because it starts from the wrong premise. The philosophy behind the proposed rule would appear to be that of my hypothetical scientist: Nobody should walk into a manhole blindfolded without being warned twice. That’s better thanwhat thecell phone companies arrived at on their own: Nobody should walk into a manhole blindfolded without being warned ineffectually. Best of all, though, would be: Nobody should walk into a manhole blindfolded, period. Manholes are dangerous!

It’s a question of default settings. Cass Sunstein, who runs regulatory policy for the Obama White House, coauthored with Richard H. Thaler a book published in 2008 called Nudge, about something called “choice architecture.” That’s a fancy term to describe organizing choices in such a way as to increase your chance of a satisfactory result. (If you want to know more and don’t want to buy the book, click here.) One of the more interesting ways to organize a choice to get a good result is through defaults. I’m a flake and a spendthrift liable never to save for retirement, but that’s OK (up to a point) because the Washington Post Co., which owns Slate, automatically withholds a chunk of my paycheck every two weeks to fund a 401(k). That’s a satisfactory result. I’m perfectly free to tell the Post Co. to stop socking my money away, but unless I affirmatively do so (which would be a very dumb thing to do), it will continue to make biweekly 401(k) contributions for me by default.

The FCC rule shouldn’t just compel cell phone companies to give consumers conspicuous warnings before they rack up big overages. They should make such overages impossible. Rather than give consumers a tool that could cap usage and prevent overages (something Verizon, incidentally, claims it already provides), the mobile carriers should cap usage themselves, either when overages begin or when some noncatastrophic overage level has been reached. At that point, consumers should receive a text or voice message alerting them that if they want to keep running up overages they must affirmatively tell the mobile carrier that they want to by dialing in some word or number. They must, in other words, leave the mobile carrier with absolutely no doubt that they have given this weighty question the attention it deserves. In the few instances where consumers signal that they understand the stakes and want to keep racking up overages anyway, they should of course be permitted to do so. Some people like walking into manholes, and it’s a free country.

Should regulation be necessary? Of course it shouldn’t. Mobile carriers shouldn’t stoop to making money in dishonorable ways. Verizon chairman Ivan Seidenberg, heralded by USA Today as a “true visionary,” should shudder at the thought that his family and friends might find out he made $17.5 million in 2009 partly by conning cell phone customers into incurring catastrophically expensive overage charges. Sadly, we don’t live in that world. So we need a government regulation—one stronger than what the FCC just put on the table.

Correction, Oct. 15, 2010: This article originally described a scene as being from Superman II. In fact, that scene was from Superman. (Return to the corrected sentence.)

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