MyBB is a database-driven application. If a nulled theme contains a script to scrape your database, the attacker can access your users' email addresses, hashed passwords, and private messages. This is a catastrophic breach of trust between a forum administrator and their community.

I delete the local database. Wipe the laptop’s SSD with a magnet. Then I check my main machine: the screenshot email is gone. No trace.

The single biggest issue with searching for is not the legal trouble—it is the security risk.