Fortunately it is possible to turn them off, although LJ don't make it easy.
Here are some instructions.
Also if there is anyone out there with Firefox not running Adblock Plus and Filterset-G ... why are you not running Adblock Plus and Filterset-G?
Another great "feature" is this new option to act like some sort of thought police on other people's journals, erm, I mean tag posts with adult or inappropriate content. I have changed my options to tag my journal as "adult themes" (which I think means I swear a lot, but don't post nekkid pics), because I'd just prefer to avoid the hassle of randoms complaining that I'm not 'child friendly'. The fucks.
Still conflicted about the morality of even voluntarily censoring access though.