Facebook and other social networks already have millions of vulnerable , clandestine underage users .
facebook和其他社交网络已有数百万易受伤害的、秘密的低龄用户。
In may 2009 , north korea detonated a clandestine nuclear test , a kilometer underground .
2009年5月,北朝鲜在地下一公里秘密进行了核试验爆破。
Leaving miles to work with dai li 's operations , donovan circumvented them both and secretly set up a separate clandestine oss intelligence collection mechanism .