During tonight’s Republican primary debate, world-class demagogue rhetorician and GOP front-runner Donald Trump said America should shut off ISIS’s access to the Internet. The terror network is disturbingly successful at spreading its propaganda and recruiting via social media. But how practical is Trump’s suggestion?

Indeed, there are countries that have cut off access to the Internet to their citizens. Iran did it in the aftermath of its 2009 elections, and Egypt pulled it off during the Arab Spring. North Korean citizens have little access to the international Internet. China limits access to certain websites. ISIS itself has banned private Internet access in strongholds like Raqqa. And even Google blocks certain types of terrible content–child pornography, for example.

But here’s the problem: America doesn’t control the Internet in the Middle East. Most of the servers that make up web infrastructure in foreign countries are not located in the United States–they are based in those other countries. Trump (as well as Bill Gates, whom earlier this week The Donald suggested might help him with this task) would either have to convince service providers in other countries to shut off Internet access in certain regions or destroy local infrastructure to cut off Internet access to ISIS–and we’re not talking about an enemy who is located in just one country.

However, to get information out of certain countries, data has to travel through specific (and sometimes limited) portals–so in theory, the U.S. could focus its efforts on those locations. And in some cases, nations rely on Internet providers outside their country–some of which are owned by American companies. So yes, there might be some ways to keep some information from traveling in and out of these countries, but preventing information from flowing within nations is perhaps more difficult. In countries where specific websites are blocked, citizens often use VPN and proxies to access them. After the Iranian elections, Twitter was banned in Iran, but Iranians found websites to post tweets on their behalf–and in theory, one could use telephones or even ham radio to do the same thing–so simply blocking platforms like YouTube inside certain countries isn’t the definitive answer, either.

And then there are satellite modems or SMS or dialup or carrier pigeon–it’s plausible one could use those mechanisms to get people outside one’s area to post to the Internet for them. Or thugs could make videos, compose tweets, or make PDFs or HTML of propaganda magazines and bundle them with scripts or human instructions on how to upload them to social platforms, like, “Plug this USB stick into a Windows machine, run propaganda.exe.”

Or maybe a clever virus or worm could temporarily disrupt ISIS’s Internet access…but that would be difficult to contain, and somehow we doubt Gates would write it or Trump could. And ISIS-friendly providers might have failover machines, so even if you hacked every server the ISPs have online, they could potentially turn on more.

So basically, it would not be simple for someone to turn off the Internet here and there–even with Bill Gates’ help.