They don't operate in Brazil, just like other millions of websites. Do you think every single website that wants to serve content to someone in Brasil should have a subsidiary in the country?

That's not how the internet works.

Having written a letter to the Brazilian Congress about (almost) this very issue (in connection with the CPI-Cibercrimes inquiry), I think some Brazilians may be surprised to know that the U.S. does not require ISPs to block connectivity to third-party foreign Internet sites that facilitate violations of U.S. laws, directly violate U.S. laws, or ignore U.S. court orders, as long as the ISPs themselves have no relationship with the sites. In fact, a proposal to begin doing so in copyright cases, known as SOPA/PIPA, was extraordinarily controversial in the U.S. and was effectively defeated. The U.S. legal system generally appears to accept that ISP blocking of third-party connectivity is simply not an available remedy, even in "clear" cases of legal violations.

That means that it is not universal or obvious that this kind of blocking would be practiced or accepted. (For example, if a Brazilian company ignored a subpoena from a U.S. court, there would not be a legal basis for the U.S. court to order ISPs to prevent Americans from accessing that company's services.)

Some portion of Brazilians think it is "obvious" that a government would never allow its citizens to access Internet services that allow or commit violations of local law, or are simply not subject to local jurisdiction at all. But it's not obvious at all.