Police on Monday announced that they had arrested three people suspected of breaking into a classified database used by Israeli courts. According to police, Moshe “Halmo” Halevi extracted thousands of sensitive documents from the database, getting a first-hand look at the often secret details of some of Israel’s most high-profile court cases — like the Holyland Towers trial, in which former prime minister Ehud Olmert is accused of influence-peddling on behalf of Jerusalem building contractors.

According to police, Halevi operated undetected for nearly four years. Most of the documents he purloined were for his own edification, police said, but he also operated on behalf of others.

One would think that the courts would have a next-to-foolproof security system, said security expert Roni Becher, a cyber-security specialist at Avnet Security Systems, but unfortunately that is not the case — not for the court database, or many others in the country.

“The court database resides on a server that is controlled by Microsoft Windows, which, because of its popularity, is a favorite target of hackers,” Becher said.

But Windows isn’t necessarily to blame, he said. Very often, Becher continued, the systems are run by administrators who fail to keep systems updated with the latest security patches and installations; when the systems fall behind, they become vulnerable to the latest hacks. And once a system is compromised — with a hacker finding his way in surreptitiously — he can set up a “back door” that only he knows about and that he can use to access the system, Becher said.

Police said that they have been investigating Halevi for several months, and that the investigation was likely to continue for a long time to come.

“The man was able to get his hands on thousands of secret documents,” said a police spokesperson. “We do not yet know the full extent of his activities, and if he was working with criminal elements.”