It’s no secret that Google Chrome is the world’s most popular browser, and while a lot of that might be owed to its quality, some believe that Google intentionally sabotaged competing browsers in order to grow in popularity. A former Mozilla executive has lashed out at the Mountain View company for repeatedly and continuously finding less-than-desirable ways to promote its own browser.

Jonathan Nightingale posted a series of tweets over the weekend, detailing some of the events that took place between Google and Mozilla over the years. Nightingale starts by pointing out that Google typically played nice with Mozilla before Chrome was a thing, but things turned sour once Google’s browser launched. While the company kept trying to convince Mozilla that both organizations were on the same side, things would often break in Firefox for no real reason.