As game ratings are more appropriate to compare to a game than film ratings, consider that the ESRB ratings are only based on a game's own content. Online interactions do not fall under the heading of that content (hence the warnings that "your game experience may change during online play").
Even online games have rules and enforcement and the like, but constant vigilance remains impossible, and is to be expected for online gaming and interactions. That doesn't itself make a game unsuitable for teenagers under 18; presumably there is some degree of internet exposure said individual is permitted in the first place, and such things cannot fall within the confines of game ratings.
Obviously that mindset applies to advertising, as well, and it seems to me that far more people are interested in policing what is/is not acceptable for someone else hypothetical 17 year old to see, forgetting their own forays into far more explicit areas at that age, than considering the context of the situation.
To that end, Maha Michi, the mere mention of Ron Jeremy is perfectly appropriate (provided no explicit descriptions or images of his work are included), and if that hypothetical 13 year old you have arbitrarily invented for yourself chooses to google him, perhaps it isn't your job to tell him what he can and cannot google. Perhaps you should leave the parenting to his parents, who surely understand the "dangers" of random google searches, as well as the functionality of SafeSearch that google itself provides, as well as parenting software that enables the blocking of sites they deem inappropriate.
(Although realistically speaking, I'd be impressed if you could point me to a 13 year old who isn't aware of porn. Ron Jeremy specifically, sure perhaps not, but in what society are you people living where everyone is so sheltered that they can't stomach the mere mention of such things?)