It's grammatically incorrect. English pluperfect tense should be used like so: Sony Hackers Seen Snooping for Months, Planting Bomb The actions of snooping an

It's grammatically incorrect. English pluperfect tense should be used like so: Sony Hackers Seen Snooping for Months, Planting Bomb The actions of snooping and planting the bomb are in the past but before the implied event of discovery which is also in the past so it must be pluperfect. The form "Having Snooped" can only be used in a pluperfect inversion such as: Having snooped around for months, the hackers planted a bomb.