Very interesting article and something that I had not considered, either.  Though I would have expected that these leasing companies would obtain written consent from a mortgage lender, because the mortgage holds priority over subsequently exectuted and recorded leases.  If a lender did foreclose, and had not approved the lease, I would expect that the lease could probably be canceled.

As for mortgages after the fact, I would not be surprised to see more lenders objecting to oil and gas leases on the title commitment.