There are many things we can do. We, as a community can blacklist coins, we can blacklist addresses, we can collect logfiles from many different servers, and then track it back to the thief. We can color stolen coins, and collectively agree to refuse to accept them. We could build in a 'coin kill switch' that if your wallet gets compromised/stolen/whatever, you can broadcast to the network so that the thieves cannot use those coins anymore. There are downsides and trade-offs to all of these things.
Care to explain how any of those things are possible?
Blacklist and color coins? Coins don't have unique serial numbers. Someone steals coins, sends them to a wallet, and sends everything from that wallet to another wallet, maybe several times, maybe to 3rd party online wallets. Now go and try to pick out any specific stolen coins from their final destination. Can't. Or forgo washing between wallets, wallet to public exchange and immediately sold at whatever pending buy value offers. MAYBE, if the person who was being stolen from was online at the exact time it was happening and could hit some panic button to raise flags before those transactions completed. But that isn't going to happen most of the time. Most of the time, the coins will have already been washed/sold before the victims are even aware, and by that time, it's too late. Already buried under a pile of legitimate coins, or already in the hands of other innocent people unaware the coins they legitimately bought were sold by a hacker who stole some of them.
Black listing addresses? What good does that do? Anyone can run as many wallets and create as many different addresses as they want. Short of arbitrarily blacklisting every address any suspected address interacts with, except those other addresses won't necessarily be complicit with what was going on. Especially when you are talking about 3rd party on-line wallets.
Coin Kill switch? I'll be quite frank. That's an incredibly stupid idea that is just asking for trouble. Kill code is something that has plagued various hardware and software in the past and present, and has a tiny fundamental problem. It can and WILL activate unexpectedly for the wrong reasons. Always does. It's always Innocent people who are always negatively affected more by such tactics than guilty people such tactics are meant to stop. Look at piracy as an example. Anti piracy measures don't effect pirates at all, just the honest users.
The main failure of these ideas are that it would require a reworking of coins networking protocols, stripping away all the key features that make them desirable to begin with. IE: No central control authority, being anonymous, etc.. Once it's made that your account is going to be associated with any coin that passes through it forever for the sake of tracking, or that other people will have the power to make chunks of coins worthless on a whim of someone claiming there was a theft, no one is going to trust or want to use it.
Finally. Don't forget that not all so called theft victims are innocent. Some are scamers, lying in an attempt to get pools/exchanges to credit them for the "theft" when it was in fact they themselves who had simply logged in through a different ip or proxy, did a password reset to keep up appearances, and send their funds to their own 2nd or 3rd newly created wallet/address to wash/sell.
ATM's/Banks have cameras. POS requires signatures/id. Theft can be proven. Crypto has neither. When someone cries they were hacked and their coins stolen, you really only have their word, and that alone is not good enough to validate blacklisting/coloring/killing coins even if such functionality was available.
i only transferred in just 1 day before 
