Yes, i currently used something of the forum as RP material i played that my character heard it from a contact. But i can no longer use these things for RP?
You can.
Anything that you read on the forum (or elsewhere) that would or should be
public knowledge, there is absolutely no reason not to use IC in whatever way you want.
If you gain OOC knowledge of things that would not, under ordinary circumstances, have been made public, using them IC in any way is ethically questionable, and you
should not do it. However, you will not be punished for doing so.
And, as should be obvious, the more important the information, the more important it is to have a legitimate IC channel for obtaining it.