Then again, if there isn't any kind of organized system behind it, of course true anarchists exist among "Anonymous".
You can't really use the term 'true anarchists' because in today's society Anarchy has more then one meaning. Example below;
[
Anarchy has more than one definition. Some use the term "anarchy" to refer to a society without a publicly enforced government or violently enforced political authority. When used in this sense, anarchy may or may not be intended to imply political disorder or lawlessness within a society.
Others, including most individuals who self-identify as anarchists, use the term to imply a system of governance, mostly theoretical at a nation state level. There are also other forms of anarchy that attempt to avoid the use of coercion, violence, force and authority, while still producing a productive and desirable society. Anarchy is also a technical issue of economic science.]
Also true about today's society is that you don't need a whole group of people to commit acts of crime, lawlessness or disorder of any kind. All a person needs is their intelligence and a computer with internet capability. Is this 'Anonymous' a person or group of persons? it's anyone's guess right now.