Yes, people know about it.
The thing is this...why are they cracking? Could it be due to people using the wrong oil? Could it be due to low oil levels and the pick ups are overheating?
I wouldn't worry too much about that because not everyone with a WRX or STi has a cracked pickup.
If I were you, I'd be more concerned with having switching to an STi oil pan to help with saving yourself from having bearing issues.
We sell a kit to help you switch it: Kronos's STI Oil Pan Swap Kit Kronos's STI Oil Pan Swap Kit  - $187.75 : Kronos Performance, Leading since 6th Century BC