The freedom of the internet has many great values. One of them is freedom of expression. A blogger can write whatever he wants. From fascist statements to extreme left wing state politics.
These are opinions. Opinions are not facts though.
As a public figure you have to understand your responsibility though. As a teenager is easily influenced by a popstar. The price for fame is political correctness. You can't say anything you think, there are social consequences.
Alternative facts or fake news is just a new word for state propaganda and it's nothing new.
Many dictators used the same tactics as Trump is using right now, calling the news from his opponents fake news and creating his own truths.
The huge social media like Facebook and Twitter do have a responsibility too. But the pace of putting information on the net that goes viral is so fast that it's hardly controllable.
The only way to get this under control is through education. I think kids need to learn how to seek for information and how to recognize fake news and extreme biased opions.
It's a complicated issue, something the internet ( and we) have to deal with as it is a dangerous thing.