Aaron Foss won a $25,000 cash prize from the Federal Trade Commission for figuring out how eliminate all those annoying robocalls that dial into your phone from a world of sleazy marketers.

The year was 2013. Using a little telephone hackery, Foss found a way of blocking spammers while still allowing the emergency alert service and other legitimate entities to call in bulk. Basically, he re-routed all calls through a service that would check them against a whitelist of legitimate operations and a blacklist of spammers, and this little trick was so effective, he soon parlayed it into a modest business.

Last year, his service, called Nomorobo, blocked 15.1 million robocalls. He uses cloud computing services—primarily Amazon Web Services and Twilio—to block Florida timeshare sellers and fake Microsoft support gurus from the 190,000 VOIP customers 1 who use his free product.

The question is why this method isn't blocking even more robocalls. Even as Nomorobo has flourished, the country's leading phone companies still avoid such call blocking. And that's rather baffling. If some dude working out of a spare room in his Long Island home can solve the robocall problem, why can't AT&T? After all, the big phone companies seem to have done a decent job of blocking text spam from their networks. And there's a federal law that lets us opt out of these robocalls.

According to AT&T, a blacklist would be a nightmare to maintain and could inadvertently block legitimate numbers. And besides, it's all the government's fault, the carriers say. But the situation is more complicated than that. The good news is that things may soon change for the better—at least in some ways.

The Education Argument

The big phone companies trace the blame back to the 1934 Telecommunications Act. The CTIA—the trade group that represents the nation's wireless carriers—says that the FCC has made it clear that, while phone companies might let consumers block specific numbers, they have a legal obligation to complete phone calls, no matter who they're from.

In fact, late last week, the CTIA wrote the FCC to tell it that the kind of blacklist approach taken by Foss's company wouldn't work. According to the lobbying group, it raises privacy concerns—and causes other problems too.

"Even assuming an accurate database of blacklisted and whitelisted numbers can be compiled and maintained, the ease with which modern equipment and software can allow a caller to spoof a caller ID would present significant challenge," the group says. "Moreover, the database for any blacklist would be very large and continually growing, such that maintaining and operating the database would be a massive undertaking."

The CTIA suggests that the FCC focus instead on consumer education. And that seems to put the phone companies in opposition to most consumers, who would love to see robocalls disappear completely. In September, a group of 39 state attorneys general told the FCC to think it over.

The States Care

The states care about this, because Americans are getting hammered by junk phone calls. Especially Americans who use land lines, which can't take advantage of services such as Nomorobo. Nearly half of the 27,000 complaints that the Indiana Attorney General's office received last year were about unwanted telephone calls.

Marguerite Sweeney, an Indiana deputy attorney general, says that robocalls have been blowing up over the past few years and the the FCC needs to spell out whether these robocalls can be blocked or not. "It's something that needs to be clarified," she says. "Perhaps when the FCC visited this subject in the past, it was in another context."

Foss acknowledges that maintaining his blacklist isn't easy, but he believes that the carriers could pull it off, given the right incentives. "I'm just an idiot who won a contest," he says. "If I can do this, I think anyone can."

The FCC is now taking public comments on the issue, but that process ends early next month. After that, the FCC will decide whether or not carriers can block them outright.

Robo Forever

Although reviled by consumers, robocalls are unlikely to go away. For one thing, voice over internet protocol technology has made them extremely cheap, and phone-number-spoofing technology has allowed them to slip past caller ID and many carrier-provided number blocking systems.

That's because most carrier phone-blocking systems force you to manually enter blocked numbers. AT&T's system, for example, allows only 20 such blocked numbers. "Usually, carriers give spots for 5-10 numbers to be blocked," Foss says. "This is woefully inadequate. The Nomorobo blacklist has over 850,000 numbers on it and changes hundreds of times per day. Try putting that in a short blacklist."

And robocalls work. Last year, researchers found that 75 percent of robocall recipients listened to at least 19 seconds of their robo-messages.

113:00 EST. Correction. An earlier version of this story stated that the Nomorobo service works with mobile phones. It runs on VOIP phones only.