Troy Hunt's HIBP aggregates billions of real-world breached accounts. While you cannot download the raw passwords directly from HIBP, you can use tools like PwnedPasswords API to check if a password exists. For wordlists, researchers look for publicly dumped breaches (e.g., Collection #1, Antipublic, Exploit.in).
Some users use separate tools to "scrape" data from the public web or use Google Dorks to find leaked databases. openbulletwordlist
