[inglor_cz]

There are big European software companies, such as Avast, but they are mostly now owned by Americans.

There aren't big European social networks, but that might be caused by the fact that Europe is linguistically and culturally very fragmented. Which does not matter as much if your product is an antivirus, but it does matter when you build a product whose value is in the sheer mass of mutually communicating users. The Anglosphere is HUGE.