A notorious internet troll has been fired from his job at a US financial services company after he was exposed as the creator of an online forum where users shared sexualised images of underage girls.

Michael Brutsch, a cat-loving grandfather from Texas who spent years posting vile messages online, claims he has received dozens of death threats since his identity was revealed last week in the New York-based blog Gawker.

The 49-year-old, who used the online pseudonym Violentacrez (pronounced violent acres), had pleaded with Gawker not to expose his identity, saying he had a disabled wife and could lose his job.

And the 49-year-old's fears proved to be well-founded. He has since been fired from his job as a computer programmer at a financial services company in Arlington, Texas.

"Everything that happens is a test from God, and how you respond to that test determines whether you pass or fail," Brutsch wrote in a new forum on Reddit, where he also claimed to have received dozens of death threats.