City's problem is that their training ground has a public pathway running alongside, offering photographers easy access.
Though United are based less than a mile away, public access is strictly limited.
"You are protecting the possibility of success," Ferguson said.
"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 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!"