Re: @Flatpackhamster @Paul
"1) It is for crappy media or Linux ISOs and I always do a separate sha256 checksum test on those."
How many times have your BT downloads had wrong checksum? (not that I have anything against checksum checking)
BT is fine for many types of software delivery. Each BT piece is hashed, so chance of delivering malformed files is rather minuscule. I've personally used P2P since Napster. The total ingress data is in terabyte range yet I can't remember malformed files getting through the clients.
Also, MS patches are signed, what makes you think Windows - or any OS - doesn't validate the updates first?
2) I can tun my BT client on and off with ease and in an obvious place, and not magically find that I have seeded many GB of OS image over some fee-paying or bandwidth restricted network route.
The setting to turn this off lies obviously within the Windows Update settings. Besides turning on/off, you can configure it to work only within your local network. If you have multiple computers the bandwidth savings can be tremendous.
But all this you knew already.