But there might exist an implicit contract between the owners of the park and the caretakers that they retain a usage right to it.
Road usage is the clear cut case, here you will loose in court if you close off a road that have been open to the public. Ownership or not, particularly if you bought the road as a part of a deal after public usage was an established tradition. Implicit contracts does need to be honored.
The stadium issue, have if i remember correctly been taken to court and the card holders got awarded compensation.
Land ownership is not actually always ownership, there countries(UK and Sweden for instance) where you cannot actually own land, but only lease it on permanent contracts.
This varies a lot from country to country some, like my native Denmark does not treat written contracts as superior to oral or implicit contracts, while some common law countries gives formal contracts preferable treatment. But i dont think that there is a western legal system where implicit contracts is not acknowledged by the courts
On the internet you have the big big problem of determining jurisdiction.
Games are just that games they are run for a purpose with a certain agenda, and in most games that agenda involves a kind of fair play doctrine that requires ingame assets to be tied to ingame actions alone and not subject to out of game financial transactions. Here theres no context of a implicit real world ownership, but this might differ Second life for instance might by encouraging real world trading of ingame assets create such a cotexts, The DNS system is an other example here there are an tradition for treating domains as property that can be treated as real asset.
What im trying to say is that the written ToS isnt the entire story of the contract.
IANYAL but im fairly sure this is a fair attempt at describing the actual law.