(Bloomberg) — Executives from Alibaba Group Holding Ltd.’s cloud division have been summoned for talks by authorities in Shanghai in connection with the theft of a vast police database, the Wall Street Journal reported, citing people familiar with the matter. China has been rocked in recent weeks by one of the largest cybersecurity breaches in the country’s history. Hackers claimed to have stolen data on as many as a billion Chinese residents after penetrating a police database. The person or group claiming the attack offered to sell the information online for the equivalent of about $200,000. According to the Journal,…