Well, most JSON parsers (haskell being a notable exception) use an amount of memory that is proportional to the size of the input, independently of whether they

Well, most JSON parsers (haskell being a notable exception) use an amount of memory that is proportional to the size of the input, independently of whether they can parse deeply nested structures or not. Saying that a parser that does not limit the nesting depth will crash your server does not make any sense. You could as well say that str_replace will crash your server.