Bitcoin has been extensively used for sex trafficking as it leaves almost no trace about the transactions made and hence was used on many porn sites too for making payments as card services to refused to provide their payment gateway. Computer science researchers at University of California have made a new tool which would help in finding out which Bitcoin transactions were used for paying on sex slave services. And can distinguish between porn and slavery. The tool is expected to be out with more details soon. With the arrival of this tool it again puts a question mark on the untraceability of Bitcoins.