On Wednesday, Meta Platforms, the parent company of such social media platforms as Facebook, Instagram, and WhatsApp, began the process of laying off up to 11,000 staff.

The reductions are the first major effort to reduce operating costs since the formation of Facebook in 2004, according to people familiar with the matter. The measure comes after a sharp plunge in digital advertising revenues disappointing earnings for the company.

According to sources, CEO Mark Zuckerberg has admitted the layoffs are due to his decisions, telling senior staff the issues the company faces “are on me.”

The staff cutbacks will affect roughly 10% of the company’s 87,000 employees.

Zuckerberg had warned staff in September that Meta would be reducing its expenses as part of a restructuring of teams.

In an employee Q&A session at the time, Zuckerberg said, “This is obviously a different mode than we’re used to operating in. For the first 18 years of the company, we basically grew quickly basically every year, and then more recently our revenue has been flat to slightly down for the first time. So we have to adjust.”

The layoffs are just the latest seen in the tech sector. Snap said in August it would layoff 20% of its workforce, and just in the last week, Twitter laid off 50% of its workforce, as Elon Musk took the helm and began seeking to improve profitability.