When starting a new company we try to pick a name that is unique.
However, now that business is global it's nearly impossible to pick a name that is not in use somewhere.
I was wondering:
Couple of years ago, I heard stories about Google trying to "inhabit" www.google.ir which is ext. for Persian-speaking users. They sued then-holders, the case went hot on the press and even the local government got involved. Although Google won the case, based on political reasons, Iranian government refused to let them control the domain.
My point is that it is very complicated for giants to pursue their rights in different countries. Thats why they choose to have a .com domain and focus advertisement on that domain.
A common strategy :
When companies enter a new country, they force their shipment partners to advertise their brand, so when a Brazilian teenager receives her new computer, she reads the big text on the truck : "WWW.COMPANY.COM"
Usually companies make a large initiation when they enter a new country, I remember McDonald entering Brazil was a huge show off, this way they make sure that everyone follows the right brand to the right company.
Every country has different laws about that situation (large multinational company starts doing business when it's name is already taken locally).
Also, it doesn't help if you choose a unique name unless you register a company in every country is the world - and even that doesn't guaranty everything because countries do split up on regular basis.
The usual solutions for the problem of moving into a country where your name is already taken are:
The simplest way is to check with google in every country that the name is not used by someone.
A brand name is not something you can/should change later (unlike logo) especially for a website. If your business is going to be big enough you really really should hire a brand naming company, such as Igor.
Protip: don't ever pick up a descriptive/functional name