If freedom of speech is absolute, how come it's not applied for private spaces and for the Internet?

That’s what it is. You have no right to use other people’s stuff. If people let you use their stuff, they can tell you how you can use it, and they can tell you to stop using it any time they want.

Insurrection

You have freedom of speech. If I loan you my computer, I can tell you not to use it for certain things, because it’s mine, you have no right to use it, and if I give you permission to use it I can tell you what you can and can’t do with it.

Why are people nowadays so into anal sex?

Revenge porn

Conspiracy

Revealing classified information

Man eats dubious street food—ends up blowing apart his GI tract - Ars Technica

And much, much more.

No freedom is absolute.

False advertising

Raw recap & reactions: Royal chaos - Cageside Seats

Insider trading

Threats of violence

Terroristic threats

How did you get to be a leftist?

HIPAA violations

Freedom of speech does not apply to:

You have freedom to travel. If I loan you my car, I can tell you not to take it out of town, because it’s mine, you have no right to use it, and if I give you permission to use it I can tell you what you can and can’t do with it.

Japan's 10,000-Year-Old Underwater 'Pyramid' Is Still One of the World’s Biggest Unsolved Mysteries—No One Knows Who Built It - The Daily Galaxy

If you’re wondering why free speech doesn’t apply to the internet, it’s because you have no right to use other people’s stuff for free.

Child pornography

Perjury

Western Force 7-54 Lions: Andy Farrell's side score eight tries in tour win in Perth - BBC

Fraud

Trade secrets