After the recent DDoS attack, London’s largest banks say they’re planning to build up an inventory of bitcoin to negotiate and pay off hackers who threaten to pull down their IT systems.

Bitcoin is the preferred currency because it cannot be traced and is highly valued by hackers and criminal groups.

Friday’s hack included infiltrating a whole host of high-traffic websites, like Netflix, GitHub, Twitter, Spotify, The New York Times, Crunchbase, Pinterest and many others. The list seems endless, with no industry being safe. The site DownDetector.com said the attack mostly affected the U.S. Experts say the reason for the disruption was that hackers unleashed a enormous distributed denial-of-service attack on the servers of Dyn, a major DNS host.

While Dyn may not be the subject of extortion demands, hackers have been threatening other businesses into paying them off with bitcoin in order to avoid risks of becoming the target of more or similar attacks.

And that’s why experts say certain banks are hoarding bitcoin in order to ready themselves in case of another attack. Technology and security expert Dr. Simon Moores said that companies are weighing the options, netting out on a decision that it may be cheaper to pay off the criminals than risk being attacked.

“Big companies are now starting to worry that an attack is no longer an information security issue; it’s a board and shareholder and customer confidence issue,” Moores told The Guardian. “What we are seeing is the weaponization of these [hacking] tools. It becomes a much broader issue than businesses ever anticipated.”

As for which banks have begun hoarding, that is not clear and may never be. Likely, other companies may take similar measures to plan for warding off future attacks.