While I can't comment on the site you are referring to, since I don't know what it is, I CAN say that OFTEN what regular members perceive as a lack of ability to adequately moderate on most forums by the moderators is USUALLY down to a mix of the members inability to understand what is required of the moderation team, what concerns have more weight than others due to the primary goal of the site ownership or management as well as unfounded feelings of having been personally slighted, which is rarely the case, because usually the moderation team members are far too busy to have time to worry about wasting any of it by being directly concerned with any one member who has not already shown an inclination for breaking the rules.
In other words, just because it seems to you like the moderators there are not doing there job, it's probably because you do not actually understand what "their job" really is. The job of moderation at any given forum is not to police things in accordance with YOUR wishes, it's to ensure that the forum runs in accordance with the wishes of those who either either own or manage the forum. Often, that is not the same as what some regular members might wish to see.
It's also possible you've run across one of those forums where "rules" are more of a peripheral concern or not a concern at all, in which case I'd advise simply avoiding that site if you feel it does not live up to your high standards.
As far as "how to take it down", the answer to that is obviously "you don't". Because if you knew how to do that you wouldn't be asking the question AND even if you did, you'd be inviting yourself into a lot of unwanted problems and legal entanglements, perhaps and probably including jail time, so it's best to at least attempt to be wise and mature in these kinds of matters and leave well enough alone. If you are offended by the way a site is run, go elsewhere.