I think in this situation there is no point in this, because you can always create another purse, or bring it to the exchange and exchange your coins for others. Therefore, this patent has not been implemented.
I think that full de-anonimization is fortunately impossible and that attempts to do that are not justified. Perhaps, they could set a sum of money and not consider anything less than that, but checking everything is corrupting one's privacy, especially taking into consideration the fact that cryptocurrencies have a rtaher unstable legal status in most of the countries.
it is usually called blockchain analysis, you can take a look at walletexplorer.com to get a feeling of what it will look like although that is already a preview of what the company behind that website is doing but it should be enough to see how it is done. it is basically linking addresses together (from the blockchain itself) and with all the other information you can find from the internet then try and link it to individuals. it is based on amounts, timing, transactions, ...
