They don't just leave people to it. Just like piracy sites, Sony isn't just shrugging their shoulders and ignoring it
Normally the sites are based out of countries with little to no piracy laws or strict laws around privacy. So companies send out letters telling them to take the site down or risk legal action and pretty much just ignore it
Sometimes depending on countries laws certain countries like the US, UK, Germany etc will get ISP's to block certain sites but it's trivial to get around with just a DNS or at worst a VPN