Monster Beverage (NASDAQ:MNST) is under attack again.

San Francisco's city attorney is suing the energy drink maker, alleging that Monster is marketing its caffeinated beverages to children and young teens.

Monster and its heavily caffeinated adrenaline-boosting beverages have come under fire since legislators and the FDA began looking into product safety concerns last year.

Monster has naturally defended itself, and it hasn't been afraid to call others out in the past.

Back in February, the country's largest energy drink maker by volume called out Starbucks (NASDAQ:SBUX) and McDonald's (NYSE:MCD) in its quarterly conference call.

Monster pointed out how Starbucks' mid-sized grande coffee serving contains more than double the caffeine of its own similar 16-ounce can. Given the popularity of Frappuccino, iced coffees, and other chilled beverages with young consumers, one can argue that both Starbucks and Monster are major players in caffeinated refreshment.

"Even McDonald's -- one of the largest restaurant chains in the U.S. -- has been remodeling their stores to provide coffee drinks, both hot and cold, in many flavors, varieties, and efficacy," Monster's CEO said during the call.

McDonald's already gets plenty of heat for marketing junk food to children through its Happy Meal offerings, but are any of these chains doing enough to make sure that their products aren't seen as appealing to children?

Monster can stand by its successful history. It has sold more than 11 billion cans of energy drinks, and rival Red Bull has moved far more than that. You don't see toddlers walking aimlessly down the street sipping Monster Energy cans out of paper bags. There are a few fatalities that some have been trying to tie to Monster consumption, but there hasn't been any conclusive findings. Monster remains readily available.

We'll have to see how this new attack plays out. Many scientists and health professionals believe that children's lower body mass makes them less tolerant to caffeine. That's a knock on Monster, but it's also something that any coffee pourer will need to keep in mind.

The new lawsuit alleges that Monster promoting an extreme sports lifestyle does make it more appealing to young consumers, but it's not as if we're talking about an animated cigarette-smoking camel here.

The attacks on Monster may never truly end. The beverage giant just needs to make sure that the same thing applies to its growth rate.

Longtime Fool contributor Rick Munarriz has no position in any stocks mentioned. The Motley Fool recommends and owns shares of McDonald's, Monster Beverage, and Starbucks. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.