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New voices within the law enforcement community called on legislators to address what they describe as the “critical threat” that encrypted private communications pose to public safety.

Organizations representing police chiefs and the nation’s prosecutors Tuesday urged lawmakers to take immediate action to bolster their ability to fight crime and combat terrorism. They say that advances in secure communication have erected “insurmountable” barriers to gathering electronic evidence of wrongdoing.

“The inability of law enforcement to overcome these barriers, known as ‘Going Dark’ in the law enforcement community, has already led to numerous instances where investigators were unable to access information that could have allowed them to successfully investigate and apprehend criminals or prevent terrorists from striking,” the groups said in a joint statement.

The Nov. 13 terrorist attacks in Paris have renewed the public debate about encryption. That puts pressure on companies such as Apple, Google parent Alphabet and Facebook, which began to offer consumers secure communications tools after documents leaked by former NSA whistleblower Edward Snowden revealed the breadth of the U.S. government’s surveillance program.

For the moment, there is no evidence to suggest terrorists used encryption to organize the Paris attacks, though Islamic State militants used one of the free, easily available encrypted apps, Telegram, to claim responsibility for the bombing of a Russian jet.

Still, federal law enforcement agencies have used the attacks to renew calls for keys to unlock private communications in the interest of safety. Republican presidential candidate Jeb Bush came out against encryption even before the attacks, though Kentucky Sen. Rand Paul has said he will ensure Americans can protect their data if he’s elected president.

Democratic presidential hopeful Hillary Clinton tried to strike a middle ground, calling on technology companies to work with Washington, D.C. “We need Silicon Valley not to view government as its adversary,” she said in a speech at the Center on Foreign Relations in New York City.