It has happened quite regularly that people are using EVM deposit addresses from a CEX in a wallet app supporting Milkomeda (Nami, sometimes even Eternl, although the warning is huge there). That does not work. The CEXes warn that you need to use the right address for the right network.
The wallet app then creates a transaction sending the ADA to Milkomeda’s bridge with the EVM target address in the metadata. The owner of that address could send them back, but the owner is the CEX. It would require someone who has access to the private keys to import them in Metamask (or Flint) and follow the steps at: https://docs.milkomeda.com/cardano/for-end-users/unwrapping-assets/ CEXes will most probably rarely do that (and it also would require to first explain to the first-level support what you even want from them before it reaches someone who could decide that in the first place).
Just from the cases I stumbled upon here and elsewhere, I could find:
- 2023-06-28: https://forum.cardano.org/t/how-can-i-receive-or-restore-my-ada/119446
https://adastat.net/transactions/46033c20fb226bafcdd559b9a638aadb8ed0eb4efeb2449be2418457b6d216f3
https://explorer-mainnet-cardano-evm.c1.milkomeda.com/address/0x5991c105eAfD4f7880A5bE3276ce3cB4B6158aca
301.9 mADA lying there untouched. - 2023-07-05: https://forum.cardano.org/t/nami-wallet-send-ada-to-binance-but-using-network-bsc-ada-not-received-in-binance/119569
https://adastat.net/transactions/7673adbb21c3ce44d3f798a96b0a1f92b2957fba7b31b4a87d737f0157245641
https://explorer-mainnet-cardano-evm.c1.milkomeda.com/address/0x90Bf5DF0bF74FBccfDf305e6943f4c6661343E1B
364.9 mADA lying there untouched. - 2024-02-06: https://x.com/sactownartist/status/1763943613090955388
https://adastat.net/transactions/298a5b6a83e42fee39830c14cafbb8c5e365cee6fe43fc95f9689416302cf72c
https://explorer-mainnet-cardano-evm.c1.milkomeda.com/address/0xBD871D3CA419fE9B0D54591de0Ff2e1D9340a808
15,999.9 mADA (!) lying there untouched. - 2024-02-27: https://x.com/Eazie323/status/1763999268245762476
https://adastat.net/transactions/483457d3405c6b2f4a42f8af9367b2903062883e030602be9e5a33c2d5a5f4c8
https://explorer-mainnet-cardano-evm.c1.milkomeda.com/address/0x30A24a40029b4aC44E937E6e0C0A12bFc627BAa6
3,999.9 mADA lying there untouched.
Obviously, each wallet app implementing Milkomeda should make the warning before executing such transactions really big.
But I’m also wondering: How much of Milkomeda’s locked ADA are these accidental “deposits”? Is there really no way they could offer to transfer them back? If the receiver did not touch them for months, would that be indication enough that this was honestly a mistake? Or could they at least talk to the CEXes and offer them an easy way to transfer back so that the users (who often only half understand what they did wrong) do not all have to try to explain to support what they want?