Just a thought: these sites need maintainance and upkeep. One source of revenue for EH is published works eg. postcards. Should you just be allowed profit from your photographs of their sites without a by-your-leave? If you set a camera up in the Louvre expecting to fire off a series of Mona Lisa postcards, would you be surprised to feel a hot hand on your collar?

For 'you' read 'one', of course. (And, "pah, 'maintainance and upkeep' in the same sentence as EH..." is not the right response from anyone.)