If you've used a dating site or app like Ok Cupid or Tinder, you'll have noticed the hundreds of fake profiles that exist on the sites, seemingly designed to make you hand over your profile to scammers.
Dating sites are, thankfully, getting better at spotting who is using their service to send thousands of spam messages.
It's not just guns and drugs that are up for sale on deep web sites.
Vendors also list guides on how to commit other illegal activities.
But there's a type of dating site scam that's far trickier to spot, and the people who operate it claim to be making thousands of dollars every month fooling vulnerable men.
The documents are often sold for small amounts of money, but the price barrier, the need to pay with Bitcoin, and the fact that they're only available on the deep web prevents the guides from being circulated widely.
The document, titled Adhrann's Updated Dating Scam 2014, lays out a method for creating fake dating site profiles, ensnaring men in conversation, and then pressuring them to send money.
They should have a burner phone, he says (a disposable phone that can be used for temporary tasks and then discarded).
The author claims that someone who operates the scam can earn up to ,000 (£9,700) every month if they operate the dating scam full-time.
Here's the overview of Adhrann's scamming guide: Adhrann advises people following his guide to take care in the way they set up their dating site profile.