Two Israeli teenagers—the alleged owners of an online attack-for-hire hacking service—were arrested last week in connection with an FBI investigation.

Itay Huri (aka "P1st" or "P1st0") and Yarden Bidani (aka "AppleJ4ck"), both 18, were questioned and released under house arrest on Friday, according to security researcher Brian Krebs.

The pair, suspected of running attack service vDOS, cannot use the Internet or any telecommunications equipment for 30 days. Police did not disclose further details of the case, Israeli news site The Marker said in a translated report.

"Booter" service vDOS, as described by Krebs, helped customers coordinate 150,000-plus distributed denial of service (DDoS) attacks, collecting more than $600,000 in two years. Dating back to September 2012, vDOS likely earned its founders $1 million or more from users who paid anywhere from $20 to $200 per month to knock other sites offline.

Bidani and Huri's identities—plus details of tens of thousands of paying customers and their targets—were exposed when vDOS was hacked earlier this year.

DDoS attacks, meanwhile, show no signs of slowing. In 2015, network infrastructure operator Verisign counted 85 percent more attacks during the fourth quarter than the same time a year before.