BRUSSELS — The European Union’s unveiling of a mobile app to check people’s age online has quickly turned sour, as cybersecurity experts found glaring privacy and security problems with the code. European Commission President Ursula von der Leyen presented the age-verification tool in Brussels on Wednesday, saying it was "technically ready" and will soon be available to use as countries move to ban kids from social media. "It is fully open source. Everyone can check the code," von der Leyen