Is Twitter guilty of aiding Hamas terrorism? That’s what a petition by the pro-Israel group Christians United for Israel (CUFI) claims. In a campaign launched—where else?—on Twitter, the group argues that providing “services” of any kind to a designated terrorist organization like Hamas is a federal crime. It has urged its members and supporters to email Twitter demanding it to ban Hamas from Twitter accounts, and to copy the U.S. Attorney’s office in San Francisco on the emails, suggesting a criminal investigation.

The group may have a point. The “material support” law is written so broadly that it makes virtually anything one does to or for a designated group a crime, even if it has no link to terrorist activity of any kind. In fact, in a case I argued in the Supreme Court two years ago, the government argued that advocating for human rights and peace in coordination with a designated group was a crime under the law. The Supreme Court agreed, and rejected our argument that such activity is protected by the First Amendment.

But why stop at Twitter? What about Google, Facebook, or Verizon, all of which have almost certainly provided their “services,” in the form of google searches, social networking, and phone and email access, to Hamas or its members. For that matter, what about Pepsi and Coca-Cola, who have surely sold soda bottles to Hamas in the Gaza Strip? What about Exxon Mobil and Shell Oil, whose gas has very likely powered Hamas vehicles? And what about public radio and CNN, whose news services are available around the world, including in Gaza?

The Twitter campaign should raise more questions about the scope of the “material support” law than about Twitter. Twitter is for all practical purposes a “common carrier,” providing its service to all comers. Would we hold a telephone company responsible for allowing a gang to use its phone lines to plan a crime, or the Postal Service responsible for delivering a package of drugs? In fact, Twitter’s own terms of service limit use to those who "are not a person barred from receiving services under the laws of the United States," although enforcing that ban is virtually impossible without investigating the identity of everyone who uses it.

The more appropriate campaign should be directed at Congress, to amend the “material support” law to limit its draconian reach. Those who knowingly and intentionally support terrorist activity should be punished. But punishing those who advocate for peace or provide common carrier access to communications simply because they may happen to come into contact with a designated group is guilt by association. Let’s start a Twitter campaign to fix that.