HP modified other peoples' printers without genuine[0] consent to make the printers less valuable. It should probably be illegal for them to do that.
I imagine there isn't an existing criminal law covering that and I'm not in favor of interpreting criminal laws creatively to expand their scope, however I could be convinced to support making a new criminal law to cover this kind of behavior.
[0] No doubt, they have some fine print in a clickwrap agreement giving themselves permission.
