Knowledge cannot be "stolen"
Which verb would describe their knowledge of this security code?
"spied"?
Whatever it is, slapping "steal" on it because what was done is wrong, and stealing is wrong, is the same sloppy logic that the copyright lobby used in the 80s/90s.
The knowledge wasn't obtained illegally or illicitly, immorally perhaps.
Illegal entry/trespass is a crime regardless of the method used however.
In your analogy copying the code (online content) isn't necessarily illegal, however using that knowledge without compensation, permission or attribution may be a crime (depending on copyright law, judges rulings etc).
What about using torrents to acquire that content?
Seeding is often considered the actual point of infringement, aka sharing copyrighted material without the right licence.
I should note I suppose that I don't agree with companies using artists or developers hard work for their own financial gain without compensation, whatever form that may take.
The problem as usual is the availability of legal loopholes when you have a team of lawyers and near infinite money.
Personal downloading is generally only a civil violation, requiring the rights holder to sue you for reparations.