Why would iTunes 9.2.1.5 automatically DELETE my iPod's entire music library???

Question

Hi everyone,
   I have an iPod Classic running software ver 1.3.  I keep (kept) my entire music library on the iPod rather than on my laptop.  I've used the iPod this way for nearly 5 years now.  This morning I connected the iPod to my Windows Vista laptop, running iTunes 9.2.1.5, which I do almost every day.
   Today was unusual.  When iTunes started up, it told me it was "syncing your iPod," then DELETED everything in my iPod's music library which wasn't purchased on the iTunes website.  Because I only bought a handful of songs from iTunes, this reduced my music library from 25 Gigs to a little less than 15 Megs.  Then iTunes crashed.
   Why would iTunes DO this???  I feel like I've been mugged.  That library took years to collect and organize and I don't have access to a lot of the original sources.  The worst part of it all is I had no inkling nor warning that anything was amiss until it was all too late.  And why would iTunes spare only what I'd purchased from the iTunes store???  Is this some sick way of ensuring Apple is the sole gateway to our music access?
         Beyond frustrated,
                  - Red Apples Only

Answer 1

It sounds like your iPod did an automatic sync. Whether or not you had it set up that way or not I'm not sure. Anyway, when your iPod automatically syncs it makes sure your iPod MATCHES your iTunes library. If you have no songs in your library (because "I keep (kept) my entire music library on the iPod rather than on my laptop") then it will delete all the songs on the iPod to match the iTunes library. The only exception is that it will copy any iTunes purchased songs from your iPod back to your computer as a way of safe-keeping your iTunes purchased songs.
As a side note, there are way too many people on this forum that don't keep their library on their computer (25 Gigs doesn't take up that much room) or at least store it on an external hard drive (they're cheap). Too many things can happen to your iPod such as; theft, damage, malfunction, or your experience that not keeping a back-up copy is risking losing a "library that took years to collect and organize". I know that I have all the CDs that make up my 31,000 song library that are all on my iPod Classic but I still keep them on my computer AND my backup hard drive. I know if I lost my iPod I really wouldn't want to rip all those CDs again, not to mention hunting down missing artwork.
CDJunkie