Hm hm, are you sure? And what is the difference between personal data and content? My pictures are pd or content? And if I publish them?
Now, obvliously, the content may contain personal data, or possibly be personal data (if it's pictures of people) and in that case I assume it would be covered.
[1] https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CEL...
Some of these are very direct like your name and address. But since other personal data can be combined to create an identifying fingerprint of you it may or may not be covered.
There's a gray area in between of course were you really need to check the legal situation, but public content on a public forum is definitely not covered.
Think about pictures: the picture of a landscape you took on a holiday doesn't identify you, but other pictures in your library might do (they contain faces, places, etc.). All together, the pictures can tell who you are and where you've been and when and with whom.