Why are there no safeguards in place to prevent sending a transaction to a used-up address?

Question

I have offered up one of my addresses to be used for donation purposes; I withdrew funds to a different address, and a now a third party has deposited funds to an address that has already been emptied out; meaning that if I withdraw funds a second time, the integrity of the key is compromised.

If this is a fundamental design flaw of IOTA, then why is there not some sort of a safe-guard in place to prevent sending fund to an account that has already been used up?

Are there use-cases that involve sending from the same address multiple times such that an implementation like this would prevent operation?

Or would this be possible to do on the node before accepting a transaction to prevent possible lost funds?

Answer 1

The "problem" is, anyone is free to send funds to any address they want, even if this address has been emptied before (the protocol is agnostic to the source & destination address).

A partial solution/safeguard could be a warning message in the GUI wallet.

In any case, as noted here https://iota.stackexchange.com/a/441/249 there is a future plan to use aliases that can be dynamically updated to always refer to the latest (un-emptied) address.