If terrorism, what stops someone from renting cabinets, bringing in "servers" loaded with explosives, and blowing the place up? Or even a molotov thrown at some

If terrorism, what stops someone from renting cabinets, bringing in "servers" loaded with explosives, and blowing the place up? Or even a molotov thrown at some of those big fibre entrances. Sorting that out, I'd imagine, would take a while.