Here is the full proposal: https://bitcointalksearch.org/topic/proposal-to-help-stop-thieves-110749
Thanks.
This is not feasible. 99% of users have encrypted wallets, which require unlocking to move any coins once they've been received. Many wallets are offline, and require a bit more work than typing a passphrase.
Second of all, this is not a feature for any baseline Bitcoin client. This violates one of the core metrics of suitability for a currency: fungibility. If I have 10 BTC, it will buy me 20 cheeseburgers, regardless of the transaction history of those 10 BTC. No coins are worth more or less, any more so than $100 bill from my wallet is different than a $100 bill from a bank vault.
In the end, there's no benefit anyway. If someone steals 1000 BTC they're not going to spend them directly. They will mix them through 100 addresses with "non-tainted" coins, and 99% of users don't care anyway, so they will accept them as payment and mix them with more good coins from legitimate users. The end result is that your client no longer believes that any coins in circulation are legitimate, and the only person you've inconvenienced is yourself.
If you would like to explore this idea, modifications could be made to notify you that somehow there's a relevant history to the coins you just received. I'm sure someone could help you modify Armory to explore this, but I'm up to my eyeballs in core feature development, and making Armory usable at all. This particular feature would be very low on the priority list.
+1, thanks for not following proposals like these.