Originally Posted by Koski
The BD570 had cinavia support at one time. A subsequent firmware upgrade supposedly removed it. I never tested it as I do not have any ripped BDs. I'm not sure if they "secretly" added it back with a newer firmware update. You can check the firmware notes on the wiki on the Dexid site.
You are right! Thanks!
Cinavia audio watermark support was added with FW 288 on 8/19/10.
Cinavia audio watermark support was removed with FW 300 on 9/9/10.
It lasted less than a month which probably indicates issues with Cinavia and/or the LG Hardware.
It hasn't been added since but there are no notes for the 362 FW on the site.
To be on the SAFE side, you should check every future update and disable the online FW update just in case there is a Cinavia implementation that can not be removed by reverting to older FW.
Also just in case you should keep all FW files handy, you never know if you'd need one or more of them. For instance, if Cinavia is implemented in future FW you may need to flash to an older FW then to a newer one and then back to an older/newer one to successfully remove Cinavia.
Here are the FW notes from the Dexid site:
Release Date: 9/9/10
File: US LG BD570 Firmware BD.8.31.300.C
Changes: [LG] This firmware is disabled "Audio watermark" DRM Cinavia audio watermark support removed
Playback issues with mkv files (BD570 EU version). Playing xvid files with external subs work fine too.
No subtitles with Blu-ray disks? 
File: US LG BD570 Firmware BD.8.31.288.C
Release Date: 8/19/10
Changes: Skipping problems with a 1080p/24Hz setting returns
Cinavia audio watermark support added
Here is the link to the Dexid site:http://www.dexid.org/wiki/LG_BD570
The 362 FW is not yet posted there but you can get it on the LG site.