We have no laws preventing corporations from banning or prohibiting certain kinds of speech, and the National Coalition Against Censorship says that’s turning into a problem for free expression.

In recent weeks, a number of large companies have made headlines for blocking the sale of certain games, and that has the NCAC, an organization that fights for more speech in politics and in art, concerned. Earlier this month, Target in Australia stopped selling open-world crime game Grand Theft Auto V. This week, Valve briefly prohibited the sale of a violent shooter called Hatred on one of the world’s biggest digital stores for PC games (before chief executive officer Gabe Newell stepped in to reverse that decision). And Apple has repeatedly blocked games that make sensitive statements about politics or sex from its iOS App Store, which is the only way to get games on the iPhone or iPad.

We asked the NCAC for its take on this trend, and its director of programs, Svetlana Mintcheva, explained why it is an issue.

“It is always troubling when corporations who control very wide sections of the market put themselves in the position of moral arbiters of what the rest of us can see and play,” said Mintcheva. “The more so as the law only protects us from government censorship.”

While the First Amendment of the Bill of Rights protects from the state banning or altering works of art, it applies in no way to private companies doing the same. But the effects on speech are similar if the corporation is big enough.

“If there were more competition in the market this would not be such a serious issue,” said Mintcheva. “But the trend is for some companies to dominate more and more of the market, which amplifies the consequences of their arbitrary decisions to suppress specific material.”

This is especially true for Apple. Unless you hack open your iPhone through what is known as “jailbreaking,” you only have access to apps and games that Apple approves. Most people are OK with this, especially when it comes to blocking malware, viruses, or broken games, but it turns into censorship if Apple bans something based on its content.

Steam has a similar level of control over the PC gaming market. While Windows is an open network that enables anyone to install any program they want, whether Steam sells it or not, Valve owns a financially significant market share of all PC game sales. When Valve banned Hatred, it was telling other developers that they would have a much more difficult time earning money from this type of expression.

This could potentially have a chilling effect on game creators.

“And while companies could possibly get support for suppressing something extremely violent [like Hatred], the same logic would allow them to suppress anything politically controversial as well, which is what Apple is doing,” said Mintcheva. “The danger is that, as we avoid becoming puppets of government, we become puppets of a handful of big corporations.”

Of course, gamers and developers have already accepted a certain level of censorship. Nintendo, Sony, Microsoft, and Valve all don’t permit pornographic “adult only” games on their platforms. And because of that, almost no developers actually make that type of content.

But now the same thing could potentially happen to other types of games. So, what can people do about it? Well, the NCAC has some ideas.

“As the only thing corporations care about is profit, and to make a profit they need customers, it makes sense for their customers to insist on being treated as people who can make their own decisions and also make decisions for their children,” said Mintcheva. “Rather than being told what is good for them by a corporate entity.”

This seemed to work with Valve and Hatred. Steam reinstated the violent game after game players and developers engaged in a vocal debate about whether it was Valve’s place to make such a call.

We asked Valve to comment on its decision-making process, and we’ll update this story with any new information.

Apple also reconsidered one of its recent acts of censorship. The company originally flagged sober political-commentary game Papers, Please for containing pornographic content by having players view immigrants nude through a body scanner. Apple apologized a few days later saying that it made a mistake.

But Apple does not put books, movies, or music through the same approval process as apps and games, which is a double standard. And when a company is the size of Apple or Steam, the NCAC believes that amount of control over a medium is dangerous.