For example, there is a website that allows to watch Japanese TV from abroad (quite expensive by the way). How one can be sure that they are not paying to scammers?
Basically, you're wishing away a number of huge problems, including (1.) that copyright attaches at the time of creation, while the owner of that copyright is often multiple steps removed from the act of creation and determined by complex legal arrangements; (2.) copyright ownership for a particular work may differ depending on political jurisdiction; (3.) copyright ownership is not the same as distribution rights, which also may vary based on political jurisdiction; (4.) it's not clear how fair use could be accommodated in such a system. It would also have the effect of favoring larger entities with more copyrighted works; i.e. Disney would have a better chance of navigating this system than an independent creator would.
So, such things are clearly on a par with terrorism or murder -- I'm sure they'll be arresting Google execs forthwith. /s
But yeah, when I was looking for a proper way to purchase, all I found was pirate versions.