Identifying people whose credit card details were stolen

Nowadays, being a victim of a fraud is not as remote a concept as people might think. While you can feel fairly secure online using double encryption and strong passwords, the old-school credit card information can be stolen relatively easily. With credit card frauds increasing at an alarming rate (http://www.economist.com/news/finance-and-economics/21596547-why-america-has-such-high-rate-payment-card-fraud-skimming-top), totaling to around $5.5 billion in 2012, it is not a laughing matter.

In this recipe, we will focus on a particular form of credit card fraud—buying from an online store. We are assuming that for some of those transactions (of a higher value), some retailers require the customers to call in and confirm their credit card details.

For the purpose of this recipe, we generated a dataset with 1,000 customers and 20 merchants. Over 50 days, our customers made over 225 K transactions for a total value of over $57 M. We also...