Pro tip for any would-be online drug kingpins: Don’t post vacation pictures on Facebook.

Ross Ulbricht was convicted in a Manhattan federal court last week for his role operating the Silk Road online marketplace. He could serve 30 years or more behind bars.

The market Ulbricht built was based on an expectation of anonymity: Silk Road servers operated within an anonymous Tor network. Transactions between buyers and sellers were conducted in bitcoin. Everything was supposedly untraceable. Yet prosecutors presented a wealth of digital evidence to convince the jury that Ulbricht was Dread Pirate Roberts, the handle used by the chief operator of the site.

How was Ulbricht nabbed? At least some of the blame can be placed on what now seems like misplaced trust in a handful of technologies Ulbricht thought would shield his identity. These are five that tripped him up:

1. Bitcoin: If you assume your bitcoins can’t be traced back to you, think again. Like cash, bitcoins aren’t tied to a person’s identity. But unlike cash, a detailed public ledger called the blockchain keeps track of each wallet a bitcoin passes through. This case showed that all law enforcement needs to do is locate the wallets on each side of a transaction and follow the money.

In Silk Road’s case, prosecutors found it relatively trivial to track profits from Silk Road as they were transferred from wallets used by the online market to wallets on Ulbricht’s laptop. Silk Road offered a service, called a tumbler, that passed bitcoins through several intermediate wallets to obscure their origin and destination. Ulbricht either didn’t use the tumbler, or if he did, it didn’t help.

2. Chat logs: So much chatter. Thousands of pages of chat logs helped prosecutors trace the growth of Silk Road. Internal communication was carried out mostly through free software called TorChat. It provides an encrypted communication channel between two parties, using a Tor network to obscure the connection between them.

Although TorChat promises encrypted messaging, Ulbricht chose to save the logs in plain text on his computer, creating a trove of conversations with fellow Silk Road administrators. In example after example, the prosecution pointed to logs where the laptop user identified himself as Dread Pirate Roberts.

In TorChat, the user has to turn on the logging function for the chats to be saved in log files. Why Ulbricht chose this option is a mystery. Perhaps he thought law enforcement agents would never see the chats because they were on an encrypted hard drive.

3. Encryption: Encryption puts a digital padlock on information so it can’t be viewed. But eventually the person with the keys has to unlock the information in order to see it. That’s why law enforcement agents had to catch Ulbricht while he was logged into the SIlk Road’s admin console.

Ulbricht occasionally took his laptop out in public to work. So agents staked out his San Francisco neighborhood until he showed up at the local library, set up his laptop and logged on. They arrested him before he could close the laptop lid, which would have logged him out and locked the contents. Ulbricht didn’t do himself any favors by working that day with his back turned to the rest of the room—something he had warned other Silk Road administrators not to do.

Because law enforcement agents snatched the laptop before Ulbricht had closed it, the contents of its hard drive were completely accessible to them, including the chat logs, a personal journal, Silk Road spreadsheets, and most importantly, Dread Pirate Roberts’ private encryption keys.