While getting a coffee today, a man walked up to me and offered me a kindle. he said he no longer wanted it and that he was looking to give it away. An avid reader, I accepted. It has no accounts on it, for when I start it up it prompts me to make a new account. Obviously, I don't want anyone stealing my credit card/other information, so is there anyway to know if it has been compromised? As well, is there any way to purge the device's contents so that I can be completely sure?
Sounds extremely strange to me and I believe that you may have received some Stolen Goods.
But none the less this is how you can delete all information.
Ensure your kindle is plugged into a power socket
Access The Kindle's Settings Menu
Select Restore / Reset to Factory Default
It's very doubtful they would have some kind of virus, or key logger after you have done these steps since they can't really inject the recover partition unless someone really knows what they are doing - since some weirdo handed you over the device It's highly unlikely unless they are MI5 are you are a naughty person ;)
The safest method would be to do a Kill Disk on it, but the problem with this is that you'd also find that it deletes the recovery partition.
PS. What Coffee Shop do you go to? Maybe I hangout in the wrong Costa LOL
It is possible that the previous owner was one of these ultra-rich people for whom money no longer has any meaning, and he honestly believed that giving the Kindle away to the nearest stranger would be the easiest and most environmental-friendly way of getting rid of it.
It is also possible that the Kindle was some highly incriminating piece of hardware that the owner was anxious to distance from his own person in the swiftest possible way. The Kindle might be stolen, or might have been involved in hacking attempts, or might contain data of questionable legality which could direct the device holder to the nearest jail (e.g. pedophile pornography, which is highly frowned upon in most countries). If that is the case, using the device, storing the device, or even resetting the device contents to factory defaults might be the source of legal trouble.
The safest course of action might be to go to the nearest police station, tell them the story of how you got the Kindle, and leave the object to them.
In fact, it's theorically possible to hack totaly a kindle and produce a fake interface ( with faked
Select Restore / Reset to Factory Default option). hackaday's paper.
As @bybe said, the safer way is to do a low-level format on disk, with all problems.
When hacked, such material is fundamentally a little computer, with network connections and a small but enough bunch of RAM.
Connected to a local network it could, for sample, open a vpn to hacker's server, browse local network and listen for command from hacker's vpn.
This could seem like a real 'trojan horse`.
So if you're working at sensible host, drop this (or go to the police, @TomLeek gave good recommendation)!
At all, this simply could be a gift...