If I leave my front door to my personal residence unlocked, and someone comes to the front door, opens it, and walks inside without permission --- is that illegal?
If you don't have a legal right to be on a piece of property, in a given structure, or in a vehicle, you're trespassing.
If you used force to gain access to the property, vehicle or structure, it will often be considered breaking and entering. Typically, these laws use a very loose definition of "force" which includes opening an unlocked door.
If you leave your door ajar, it's just trespassing. If you had to open the door, it's probably B&E even if you didn't break anything to do it.
What about walking up to someone's door and knocking to see whos home? What if there is a picket fence around the yard with a latched gate that you have to open to get to the front door?
In the only jurisdiction where I've actually read the trespass law, it stated that a "legal fence" was sufficient to indicate no trespass, and that a "legal fence" was any number of acceptable structures that were at least 4 feet high.
In that context, a wall of a house being at least four feet high, would carry an implicit "No Trespassing" sign on it, but the picket fence would not. However, if the property had an obvious path to an entryway, then walking up that path to the entryway was not trespass. So walking through a picket fence with a low-latch would not be trespass, unless the pickets were four feet high, or if the latch was locked.
To the best of my knowledge, no - your place of residence is considered to be private property and thus there is an implicit "no access without authorization".
I think a better comparison would be comparing LinkedIn to a public property (such as a commercial store) and thus there is an implicit "access allowed until revoked".
I think that realistically, there are strong parallels to this being a customer/company dispute over who has access to the company's store. The door (HTTP protocol) has to be walked through for the customer to see the wares (LinkedIn profiles) and can be guarded by security (some form of authorization).
I think the question being asked is a valid one - should a company have the right to bar access to otherwise public information if the customer is not tampering with your system? If so, to what extent? If undesirable robots shouldn't be turned away what about DDOS traffic? What forms of flow control become legal in this case?
I'm honestly curious what the courts decide and how that may impact other websites that have tried to combat scraping, such as Craigslist.
Depends on the person (stranger vs close uncle vs not close uncle, etc.), but in general, yes it is. It's also illegal in some states to leave your keys in your running car. It's still illegal for someone to get in and drive off.
Not if it's a personal residence. Entering someone else's property is trespass unless you have license. When private property is open to the public, there is an implied invitation to the public to enter, so you have license to do so unless it's revoked. With a personal residence, however, there is no implied license for strangers to enter (though there might be based on the parties' relationships or prior dealings).
No, you just think it is. The intruder must be there to commit a further crime, usually a violent one.
An intruder must be making (or have made) an attempt to unlawfully or forcibly enter an occupied
residence, business, or vehicle.
The intruder must be acting unlawfully (the castle doctrine does not allow a right to use force
against officers of the law, acting in the course of their legal duties).
The occupant(s) of the home must reasonably believe the intruder intends to inflict serious bodily
harm or death upon an occupant of the home. Some states apply the Castle Doctrine if the occupant(s) of the home
reasonably believe the intruder intends to commit a lesser felony such as arson or burglary.
The occupant(s) of the home must not have provoked or instigated an intrusion; or, provoked/instigated
an intruder's threat or use of deadly force.
well, 'breaking and entering' in the US requires that something (i.e., the door) actually be broken in the process of entering the house...otherwise that charge doesn't apply.
Fun aside: breaking and entering is referred to as such in English Common Law because criminals used to bust through the wattle and daub walls to break in, thus housebreaking, or breaking and entering. [1]
I'm actually not sure.