I'm fairly certain that the telco huts or CO's have to accomodate multiple groups having access, so I'd bet that a padlock probably is a tough sell :( Its very interesting that the 'critical infrastructure' has seemingly loose security on such vital parts.
Actually padlocks are quite common. When multiple organizations need entrance into a single gated area, its standard practice to have each of them put a padlock onto a string, separated by only one or two links of chain. When you want access you just unlock your padlock. Low tech but works pretty well considering the weak point in a chain-link fence is usually the chain-link, at least where a serious saboteur is concerned. We are collocated in about a hundred ROW huts and the security is usually aimed at preventing casual vandalism. -vb