Now the question is, what do you really think happens when the recycle bin is emptied thus disposing off the junk it contains? Does the computer simply just "take out the trash?" or does it simply just forget they ever existed in the first place?
Come to think of it, if it does indeed take out the trash, won't the continuous trash accumulate to a significant amount thus occupying much needed space "somewhere else"? These and many more are some of the ridiculous questions which I once did ask myself. These questions came about especially after reading somewhere that AVAST was somehow able to use "data forensic analysis" to recover and pull off more than 40,000 deleted texts, pictures and emails from 20 previously owned android phones it purchased from e-bay. And just in case you were wondering, of course they did find over 250 male nude supposedly "deleted" photos along with roughly 750 for women both scantily clad and fully undressed(source). The report even goes further to say that one guy who previously owned one of the phones had a serious affinity for anime porn!(Haha, what a crazy world we live in!). So this really begs the question; how can I fully and convincingly know I have completely or permanently deleted files from my phone or computer without them being ever recovered again? Well, the answer and truth is you don't. But then again, if there's always that chance that my deleted files like my private pictures, texts and emails can be fully recovered and re-posted by my enemies on facebook, twitter and instagram for public viewing, what then is the point of deleting them in the first place? Well, again I guess that's a chance we'll all have to take and something we'll have to live with if it eventually does happen, although maybe you should really just stop taking and sending nudes. At least that way you'll have some much needed inner peace and absolutely nothing of that nature to worry about. But what really happens when a file is permanently deleted? Let's see for ourselves.
Therefore when a file is permanently deleted, the computer simply removes the "pointers" or "reference" which once or previously referenced and pointed to the part on the hard drive where the file was stored, and thus newer files can be stored on that very space formerly reserved for the just deleted file. So, in summary the file is still there on the hard drive but is now unreadable by the computer, which is the primary reason why data recovery processes can be initiated and carried out effectively by data analysts and specialists who make use of special data recovery tools and software to retrieve such supposedly "deleted" data.
So in essence, to completely delete a file you would have to literally pulverize that very file and burn it completely to ashes thus ensuring that there are no remains or left overs of the file simply by completely overwriting that very file with new data. And although many persons may do between one to 40 overwrites which is crazy and way over the top, it still may not be enough especially for hard drives with "BAD SECTORS" which are parts of a drive that devices cannot access and are unwriteable due to possible physical damage to the drive's components.
With these and many more facts and reasons just considered, it becomes really obvious that to permanently delete any file or data you may need to physically destroy the device housing it which is totally insane, although that's the only way to totally and completely guarantee that your files will never ever see the light of day. But what if you took a bad picture with your phone, deleted it and then smashed the phone to the ground, and then you picked up the pieces and threw them into a blast furnace but yet somehow you're still worried that someone might be able to use some weird and crazy means to recover and see the picture someday? Well, you need not worry anymore because very soon, in approximately 5.4 billion years the sun will become the ultimate shredder and destroyer, as it will by then become a burning red giant large enough to swallow earth whole along with all your unwanted files and data you so desperately want to destroy and DELETE!