Though United are based less than a mile away, the situation there could not be more different, as what public access there is affords no clear view of the training ground itself.
And Ferguson said: "You are protecting the possibility of success."
He went on: "Do ICI send an email to another bio chemicals company telling them their new discoveries in drugs? Does any major company tell its opponents what they are doing? I am sure they don't.
"Unfortunately football has a media profile which means cameramen want to be at training sessions. I think that is ridiculous but it makes it very difficult for a coach to do their work because you don't know where the information can go.
"I think it stopped at Real Madrid under Jose Mourinho, but there are some places where the press are in every day. This is what they expect. I know it happens in Italy. I don't know how you can do your tactical work.
"Fortunately, at our place, we can guard against it to a decent degree," Ferguson added, before joking: "Sometimes we get a photographer wandering over in the woods - but we can put wolves in there!"