BEIJING (AP) — Beijing hotly denies accusations of official involvement in massive cyberattacks against foreign targets, insinuating such activity is the work of rogues. But at least one element cited by Internet experts points to professional cyberspies: China’s hackers take the weekend off.

Accusations of state-sanctioned hacking took center stage this past week following a detailed report by a U.S.-based Internet security firm Mandiant that added to growing suspicions that the Chinese military is not only stealing national defense secrets and harassing dissidents but also pilfering information from foreign companies that could be worth millions or even billions of dollars.