Some of the systems have been hackable/hacked by non-authorized users. There's been stories every so often here on HN.
However, there are lights that do not ever open up to pedestrian crossing unless you hit the button, which irritates me.
The crossing of the A60 into Rempstone is one such example.
https://www.google.com/maps?ll=41.869753,-87.648017&spn=...
It turns red immediately when you press the button. When I was in college, I would entertain myself between classes by going over, pressing the button just as the upstream light turned green and cars began accelerating, and then not crossing the street.
This, incidentally, is probably why most lights don't change immediately.
Not everyone understands that you need to keep standing on the pad, or that the bike crossing doesn’t last long enough to walk all the way across.
They may have a detector (ir-red/mircowave/inductive loop) that detects your approach. At night, as they may be no conflicting demands - the side road will change Green ASAP.
Only a few cities (notably New York, San Francisco, Chicago) believe in pedestrians.
You can know if someone is crossing a street in Boulder from Denver :)