jeff bezos amazon ceo founderCEO and founder of Amazon Jeff BezosAlex Wong/Getty Images

Amazon made sure to mention it had “listened to our critics ” when the company announced Tuesday it was raising the minimum wage for its workers to $15 an hour.

Indeed, Amazon’s pay practices have faced a lot of scrutiny — Sen. Bernie Sanders has been one of the most visible and ardent critics of Amazon. Most recently, the senator introduced a bill to Congress named after CEO Jeff Bezos, and has criticized the company for its practices in terms of employee pay, benefits and safety.

But the flack Amazon has gotten hasn’t come from Sanders alone. As the largest online retailer in the United States, the company has been subject to scrutiny from politicians, activist groups, and small businesses as it continues to grow.

Here’s a look at the biggest criticisms leveled against Amazon in the past year: