【明報專訊】NEXT Thursday is the 60th anniversary of the foundation of the People's Republic of China. To make sure that nothing untoward will happen on National Day, the authorities have raised the alert level in all places on the mainland, especially in Beijing, the capital. They have taken special security measures. As things are complicated on the mainland and elsewhere, it is understandable for them to have done so. However, in Beijing, not only do the authorities monitor subway carriages, but they have also had microphones installed in all taxis. They listen in on fares' conversations. This measure is questionable. It violates privacy and strengthens the unfavourable impression that, in China, an omnipresent Big Brother keeps the people under constant surveillance.