LTT is Linus Tech Tips, originally a YT channel where Linus and others discussed technology products, particularly pc gaming hardware. They got kinda big, and became a whole tech media company.

Madison was a former employee of the company who alleges that LTT leadership created a hostile work environment for her. Her accusations paint the company as filled with unempathetic tech bros who demand way too much productivity out of staff. Most seriously, there were accusations of sexual harassment by different team members, though not Linus himself that I'm aware of. She has a social media thread where she describes these accusations in detail and depth. If true they are very damning.