Is selling "Likes", "Views", "Followers" illegal ?

Hello,

I'm living in an European country and I would like to know if selling Insta/Facebook "Likes", Twitter "Followers" and YouTube view is illegal ? If so, why ?

No it's not illegal. There are tons of social media companies that sell this kind of stuff.

You can do it.
But they are not accpeted by terms and conditions of insta\facebook
By there terms you cant do it and it is illegal according to there terms.
But all do it ,you can too

Thank you more suggestions ?

It's perfectly legal. Those are free services which can ban you for no reason, so whoever sells these things may be selling a product that quickly loses value. That's all you gotta watch for - you buy 20k likes, but 10k get banned overnight...no refunds, etc.

So far it has not been regulated by any laws that I know of.

Spamming Google, Facebook, etc is perfectly legal, though they'd love to make it illegal. Since they're out there to collect your personal data, they don't want to restrict their user base by suing everyone. Plus it's kinda Internet Culture to allow a certain level of harmless black hat to go on, otherwise it becomes a closed and controlled system(though Google is trying hard to make it so, and they're failing miserably while at it....).