If Democrats, Republicans, and the telecommunications industry can agree on anything, it's that robocalls are the worst. That's why the Federal Communications Commission passed rules today that expand the authority of phone companies to block unwanted phone calls. Short version: If a phone number seems at all likely to be bogus, companies can block it.

The law forbids marketers from calling people who are on the Do Not Call list. Yet according to the FCC, consumers last year received about 2.4 billion robocalls per month. And these calls are more than just an annoyance: Last year the IRS estimated that scammers posing as tax collectors used robocalls to make off with about $26.5 million from the public.

The FCC receives more complaints every month about robocalls than any other issue. But the agency struggles to track down culprits because most hide their real numbers using the same sorts of technology that make it possible to use a standard phone number with your Skype or Google Voice account. In most cases, the FCC says, robocallers don't even use real phone numbers. They rely on mimicking inactive or unassigned phone numbers—spoofing, in industry lingo.

With tracking down the culprits out of the question, phone companies have turned to automated blocking tools like Nomorobo, which blocks known robocallers while whitelisting emergency numbers. This practice is perfectly legal under FCC rules—in fact, the agency actively encourages carriers to provide customers with these types of tools. But some companies, including AT&T, complained that FCC rules against blocking calls prohibited them from aggressively targeting telemarketers for fear of accidentally blocking legitimate callers.

Today the FCC approved a proposal created in collaboration with a "strike force" that included AT&T, Apple, Google, and Comcast. Once the proposal's rules go into effect, carriers will have permission to block all calls from numbers that can't possibly be valid, such as those that aren't assigned to anyone or phone numbers that simply don't exist (like "000-000-0000").

"There is no reason why any legitimate caller should be spoofing an unassigned or invalid phone number," FCC chair Ajit Pai wrote in a blog post announcing the proposal. "It’s just a way for scammers to evade the law."

It's possible scammers will move on to another technique once the proposal goes into effect, but for the time being at least your carrier can no longer blame the government for not blocking most robocalls.