The webcam - it went nowhere in the plot
It was exceedingly obvious when the young "80s skateboard guy" was web-chatting with his girlfriend on his laptop (a horribly unrealistic idea to begin with), that the webcam would be used to look in on the hostage situation. However, this plot element went nowhere! After the live stream was established & broadcast on the news, it was pretty much forgotten and didn't factor into the plot whatsoever. Except to allow the whole of NYC to witness Ryder murdering the 'tough-looking black guy'. Furthermore, because Ryder was monitoring news coverage, he would've seen that they were being spied on. When that bald guy finally discovers it, the damn thing runs out of battery power! And then, conveniently, the boy gets enough power back to profess his love to his girlfriend...
Stupid, obvious macguffin, cheap writing, and lazy execution.