As I said, there are two goals for destroying a burner -
1-be sure the police do not associate a phone with the perp
2-make it impossible to determine activities done with the phone.
Obviously with Hemisphere, compromising #1 leads to #2. Similarly, too much #2 activity can probably help the police find #1. Cell phone use is an arms race. There’s the story that gangs love older flip phones, since they have no GPS and only cell tower data can be used to locate the phone. Note that as I understand, when phones switched to digital from analog, there was an added feature where the power level of the phone adjusted to prevent nearer phones overwhelming the tower and drowning out far phones - so the phone company can even still get a rough idea of distance from the tower, GPS or no; and because typically multiple towers can “hear” the phone, they can triangulate. (Important to allow hand-off as the phone moves closer to a different tower).
The ideal burner strategy is to obtain a pair of phones, use them for a limited purpose and for a limited time, then dispose of them so that the SIM or IMEI cannot be read. Even then, if you are the only burner user - the cops will figure that out by database diving; plus IIRC the IMEI indicates the make. Use too many the same model, cops will go “Aha! Bugsy has a big stash of old Nokia flips!” Be too regular in your patterns, or use the same phone to receive orders from customers as to call your main supplier, etc. - patterns easy to discern.
And so on. Like anything else criminal or military, it’s an ongoing arms race.
From what I’ve heard, if the feds are actively watching you, there isn’t much you can do. However, the likelihood of the state expending a lot of resources on a trashed phone found in a dumpster somewhere is pretty low. Things like burner phones probably work better by helping you stay off radar, and making it harder to track you. Usually, they find the other suspects by tracking who is calling someone who is on their radar.
As pointed out up-thread, the phone itself is eminently traceable – its IMEI is unique to it and transmitted to the cell phone network as long as the phone has power (even if it’s “off”). Regardless of what SIM it has or how many SIMs it has (single, multiple, or even none).
If I see a phone on the ground, I might do the good citizen thing and pick it up, see if it turns on and if there’s a phone# I can call to return it. If I see a broken phone I’d just think “rubbish” and leave it or chuck it in the trash.
Sort of a myth. If a phone is “powered off” it’s not doing anything radio-like. (I.e. on iPhone, “slide to power off”). Whereas, if the phone is blank not lit up but waiting for a call, will ring if called - then it is still pinging the nearest tower every second or so.
Another insidious big brother feature is that the phone may tell nearby Wifi it is available, if it has wifi enabled. So, a properly configured access point can enumerate all the phones going by, and their unique MAC address is equally identifying.
Most of them are broken - which would be the case of ones in this thread.
I found a pristine iPhone and a pristine iPad both of which had lock codes. I found the iPad in a state park and turned it into the rangers - it was later recovered by its owner I was led to believe. I was unable to get the iPhone back to its owner.
Having to accompany someone to the dump a few days ago; in one of those huge dumpsters/skips the size of a caravan I saw within reach a Seagate 3.5 hard disk sitting on top of heavy duty assorted ironware.
I snaffled it and it was tiny, 250GB; but I shoved it on my Mint rig in an external enclosure and it worked fine, full of Windows stuff I didn’t bother to pry into. ( Formatted it withGParted to Ext4 and will use it just for longterm storage. ) No doubt a bit of rain etc. in a day or so would soon have made it valueless.
Thing is once you let a thing go, you don’t know — and have no legal ownership any more — who will pick it up; how much they will examine it and what they will find.