I understand that some landlords have it written into their leases that all network wiring will be removed when the lease ends because of this very reason. One

I understand that some landlords have it written into their leases that all network wiring will be removed when the lease ends because of this very reason. One building we were in had Twinax above the drop-ceiling (used for System-36 and AS/400 terminals). Plus dozens of multi-pair phone cables that had been left there. I wish I had all that copper now that prices are much higher.