Originally Posted by LurkerLito
They can't do it. Because technically them deleting the software could be considered the same as them modifying the hardware. Since you own the hardware they cannot forcibly break it by removing the software that is stored on your equipment. Software is based on "License to use". They can terminate the license to use so by using the software you were committing copyright infringement, but terminating your right to use the software does not mean they are given the right to remove the software from your hardware.
No removing software would not be in violation. Like you stated they can revoke the license to use that software, which they can do by locking it or removing it. It's no different with Windows Validation system that can stop windows from operating at its full capabilities or randomly reboot.
Sony can argue that your license extends to the OS so disabling it to violators is there right. They are not stopping users from using the "hardware"... since thats something physical... they can make it still boot and just display a message that access to the PS3 OS has been revoked.