Among the many questions highlighted by last month’s Malaysia Airlines Flight 370 disappearance was the prevalence of stolen passports (two passengers on board were flying with stolen identities). A recent article published in USA Today noted that Interpol’s database lists more than 40 million stolen travel documents (most of them passports) since 2002. Despite heavy security measures at airports in a post-911 world, passport security is still fairly lax (sometimes non-existent). Only a few countries systematically check them at the gate. So where do these stolen passports go? The black market, where they’re sold to everyone from illegal immigrants, prostitutes and criminals to terrorists.

Like stolen credit cards, having your passport stolen can be a traumatic experience. While practicing safety precautions is always advised—keep all of your bags close to your body, never leave items unattended, lock your suitcases—pick-pockets can still snatch your travel documents and catch you unaware. Before traveling overseas, it’s always best to make a couple of copies of your passport card so you’ll have all relevant information needed to replace the card in a worst-case scenario. If you are traveling abroad and your passport is stolen, you won’t be allowed back in the country until you have a new one. So, if you find yourself in this position, there are a few basic steps you will need to take to replace your passport:

1. Contact the nearest U.S. embassy or consulate
2. Speak to the Consular Section to report your missing passport.
3. You’ll be directed to where you’ll need to go to replace your passport, get a new photo, etc.
4. To replace your passport, you’ll need a photo ID, a passport photo, evidence of U.S. citizenship (which is where a copy of your passport comes in handy), your plane ticket, a DS-11 Application for Passport and a DS-64 Statement Regarding a Lost or Stolen Passport.

Read more precautions and replacement steps here.