The brutal murder of journalist James Foley and now Steven Sotloff in Syria has sparked disbelief and raw outrage. Now, a broader debate is opening about the role of the media in conflict zones: Are some stories just too dangerous for journalists to cover? Should governments pay ransom when reporters are kidnapped? How should the media cover terrorist propaganda like that surrounding the beheading of these journalists?

Answering these questions requires accurate and timely information from conflict zones, precisely the kind of thing journalists risk their lives to report.

But there is one story the media has not been covering fully, at least until recently. And that is the story of the kidnappings themselves. Under a practice known as a “media blackout,” news organizations have routinely suppressed information about the widespread abductions of journalists and others that have taken place in Syria, Somalia, Pakistan, and other countries around the world. The number of journalists kidnapped each year varies greatly from conflict to conflict, but there has never been anything like Syria. More than 80 journalists have been kidnapped since the conflict erupted in 2011.

As head of the Committee to Protect Journalists (CPJ), I’ve been involved in far too many of these cases over the years. I’ve provided support from media organizations and families; I’ve participated in campaigns, both and public and private, to win the release of kidnapped reporters; and I’ve debriefed many journalists and media organizations about their experience.

Initially, I supported the use of media blackouts in selective cases. But more recently I have come to doubt that it is an effective strategy. The rationale behind blackouts is that they can save lives by facilitating hostage negotiations. But I have seen scant evidence to support this. Meanwhile, because the news is suppressed and sometimes never released, blackouts themselves stifle the public debate and undermine the media’s own credibility.

After Foley went missing while reporting in Syria on November 22, 2012, his family and editors initially asked for a blackout. But after much reflection, they decided to go public and in January 2013 launched a public campaign for his release. I believe this was the right decision. The terrible killing of Sotloff, whose abduction was not reported until ISIS itself broke the news in the Foley video, makes clear that blackouts are not likely to effect the outcome at least as far is ISIS is concerned.

In Foley’s case, the public campaign did put pressure on US authorities, which launched an unsuccessful military operation to try to rescue Foley, Sotloff, and other hostages. Media coverage of Foley’s kidnapping also raised public awareness about the perilous conditions in which journalists work in Syria. Finally, it prevented Foley’s depraved killers from using the video of his execution to define him as a helpless victim. Indeed, blackouts may well serve the interests of Islamic militants who peddle in murder videos since they make it easier for such groups to control the message.

The kidnapping of journalists is not a new phenomenon. From Lebanon to Colombia, militant, guerrilla and criminal groups have used media kidnappings to extract ransom, generate publicity, and shape coverage. Journalists are uniquely vulnerable because they need to interact directly with the militants and where possible gain their trust.

At first, the response to such kidnappings was to use the power of the media itself to put pressure on the perpetrators to release their hostage. That strategy worked so long as those holding the journalist were hurt by the negative publicity.

But that logic was subverted by the 2002 kidnapping and killing of Daniel Pearl in Pakistan. After The Wall Street Journal reporter was abducted in Karachi, media organizations drew from the old playbook, undertaking a campaign to humanize Pearl and employing prominent Muslims like Muhammad Ali and Yusuf Islam (formerly Cat Stevens) to appeal directly to his captors. But this media strategy inadvertently served Al Qaeda, which in turn used Pearl as a political prop to spread a message of ruthlessness and terror. The media campaign only heightened the trauma and visibility of the kidnappers. Meanwhile, Pearl’s videotaped beheading became a terrorist motif, emulated not only by Islamic groups as in the Foley case, but by drug gangs in Mexico.

In the aftermath of the Pearl killing, media organizations began to rethink their response to kidnappings. Intensive publicity, it was argued, not only helps disseminate the terror message, it can complicate sensitive hostage negotiations. As media kidnappings soared amidst the declining security environment in Iraq this new thinking was increasingly applied.

Joel Simon is the executive director of the Committee to Protect Journalists. This essay is adapted from The New Censorship: Inside the Global Battle for Media Freedom, which will be published by Columbia University Press in November.