We've recognized that we are receiving an influx of new users, most likely due to Pokemon GO and Sun & Moon's imminent arrival. However, we've also noticed an influx of hacked Pokemon being traded, and some scammers popping up.
Something I've noticed is that a lot of hacks were 'received over Wonder Trade'. If you received a 6IV shiny event Pokemon there is a good chance it is not legitimate. In fact, if you receive any Event Pokemon I advise you to check its information against an event database such as the one Bulbapedia has.
Please make sure you know the legal status of any Event Pokemon you are trading.