I had a SPOT for a very short period of time. I found that the unreliability of the device caused more angst than help (read: "It stopped tracking! Did she fall off a cliff??!!) After one particularly malfunction-caused hysteria spat, I threw the #$%^%$!! thing in the garbage. Yup -- I threw it in the garbage without removing the battery, disabling it, cancelling it....dumb$T that I can bee in a fit of anger.
Six months pass.
One morning, I receive a bunch of hysterical calls from the same folks who drove me to trash the SPOT, only THIS time, it was sending out mayday texts. Now for certain, I had surely fallen or jumped off a cliff, and the SPOT was confirming it AND getting me back for trashing it. We all surmised (after the hysteria died down) that the device was being crushed in a landfill, and the messages were the last gasp attempt to save us both. It could have been worse; at least it did not call 911.
I have since gone back to leaving plans, maps, return times, etc -- much more reliable.
The body betrays and the weather conspires, hopefully, not on the same day.