That was truly horrid but not surprising.
Trail cams have their uses however what people forget is that they were designed for catching animals and not humans.
I recently did a trial across several and the head and shoulders winner was the Bushnell aggressor no glow
http://bushnell.com/hunting/trail-camer ... or-no-glow
Why no glow? Most units use 88Nm IR that glows and are fairly obvious to the human eye, my wife spotted one immediately (Bushnell Essential HD).
The Aggressor uses a 940Nm unit with enough oomph to punch out further than many of the 880 units (higher wavelength is often harder to see but shorter range).
It also has a good long detection range that deals well with crossing as well as head on targets.
It also has a very high resolution which is where its usefulness comes in. Most of these are designed to be set at 6 feet above the deck or so, human eyeline. IF you have good res, decent IR and good PIR and IR reach, the res will allow you to mount the unit higher and still get a decent image, however...beware baseball caps. Or mount low and cam up well.
IR at night is always a problem as most people look totally different and many non mil cammo paterns are rendered useless as they dont reflect IR so look like plain material.
The Agressor also does audio and works reasonably well on a vehicle at angles up to about 30 deg.
The issue with the GSM ones is that although ideally you may get an image of the perp, a lot of these units depend on 3rd party servers or operate in areas that are remote and often cannot get enough bandwidth or signal to be reliable.
for cammo....ivy covered tree/artificial Ivy, or cover with sniper tape and glue moss to it. You will be surprised just how quickly they melt, but if a person is surveillance aware you are going to have to be a bit lucky/clever.
