A “valid” address locking up funds sent to it without recourse is /dev/null.
A “valid” address locking up funds sent to it without recourse is /dev/null.
The user in the submission did not send funds to a invalid address. The address is valid, as otherwise funds wouldn't be able to be sent to it (the wallet would not allow you, nor the protocol, nor the miner/validators). The address happens to belong to a contract, that can also hold funds, similarly to accounts.
Now, every address/account/contract has a private-key behind it, that allows the owner of the private-key to transfer out of the address/account/contract, but it's impossible to know if the owner actually still has the private-key.
Similarly to how you can't know if john@example.com actually has access to his email account (maybe he forgot his password?), you can't know if an address actually has the possibility of moving the funds out of the address, as the private-key can have been thrown/forgotten/lost.
The stakes are a little bit higher when you’re sending money instead of emails.
Simply said: you cannot send funds to invalid addresses on Ethereum.
A protocol could conceivably require the recipient to verify they're holding the private key for the address before the transaction can take place.
Yet here we are.