More than 2,100 gaming accounts were closed as part of Operation: Game Over run by New York's attorney general.
It was able to target the accounts because registered sex offenders are required to surrender details of their online aliases.
Blizzard, Microsoft, Sony, NCSoft and many other game firms are backing the purge, aimed at protecting children.
"The internet is the crime scene of the 21st Century, and we must ensure that online video game platforms do not become a digital playground for dangerous predators," said New York's attorney general Eric Schneiderman in a statement.
Mr Schneiderman said the action would make online gaming communities a safer place for children. Many parents did not know, he said, that online gaming platforms and services let players communicate anonymously. However, he added, offenders had used this capability in the past to contact and "groom" children they later went on to abuse.
New York's Electronic Securing and Targeting of Online Predators Act, known as the e-STOP law, requires convicted sex offenders to tell the state which email addresses, login names, screen identities and other online aliases they use. These are then passed on to game and web firms that have signed up to help the programme.
Gaming accounts on Xbox Live, PlayStation Network, World of Warcraft, Guild Wars, Gaia Online and many others have been deleted as a result of the law.
This action builds on the first stage of the e-STOP programme that saw more than 3,500 online accounts used by sex offenders shut down.
Hundreds of accounts for online games used by registered sex offenders have been shut down in the US.