Should be recognised that not all data is eligible for copyright. "Facts" is a broad category of exemption with strange case law. It may be relevant here if the data being scraped is available elsewhere.

Note also that in some places, databases are explicity exempt from this "facts" exemption if you made considerable effort in compiling the database. (IANAL)

Yes indeed. See:

https://en.wikipedia.org/wiki/Feist_Publications,_Inc.,_v._R....

Does the same thing apply to newsletters? Let's say I get a bunch of free newsletters to my inbox and share them on my website (I mean literally copy the body so people don't have to sign up for the newsletter themselves), does it count as copyright infringement?

Also not a lawyer buy If you're in europe I believe there's also something called database rights which gives some protection to people that gather data from different sources event if they are not content creator.

Correct, the database directive: https://en.wikipedia.org/wiki/Database_Directive

Aka Directive 96/9/EC of the European Parliament

OP mentioned that they just buy the data from someone else and therefore OP is not a database rights holder.

What if I created my content by slightly altering other content? Like writing a news article from a Reuters press release, how much difference does there need to be?

Seems like a pretty hard line to draw.

If it's based on the other content, then it is a derived work and copyright infringement.

Keep in mind that copyright is for creative works. Facts can not be copyrighted. In a news article, it is the expression of the facts that covers the copyright, not the facts themselves. So you can definitely write an article stating the same facts as a Reuters press release (and be even based on that press release). You just can't base your prose on their prose. You have to completely rewrite it as a human -- it has to be an artefact, not an automated process.

However, there is another class of copyright for collections. A collection of facts can be copyrighted. You can't copy the same collection of the facts, nor a substantial portion of the collection. You can take individual facts out of the collection and include them in a creative work, but you can't just grab facts one at a time and create a new collection -- that would be a derived work.

Like all laws, copyright law is subject to interpretation by humans (lawyers and judges). While you might think that you are satisfying the law, they may disagree. To avoid that circumstance it is best to stay in an area where it is obvious to everyone that you are within the law. If you don't mind being sued, then you can try to push the boundaries. It is your choice.

You sound like you're asking this question as if it's a brand new question that nobody has ever thought of before, instead of something core to the entire idea of copyright: https://en.wikipedia.org/wiki/Derivative_work

Yes, it is a hard line to draw. It is advisable that if your business is dependent on being on the right side of copyright issues that you simply stay well away from the line.

It's actually extremely easy to detect. Even if you change verbiage and move around paragraphs. Most sham content providers are much more sloppy than moving paragraphs around, and will just use a thesaurus to modify verbiage. This typically makes it extremely easy to detect. Because, even though a word might be a synonym, it might not work grammatically in it's context.

> Seems like a pretty hard line to draw.

All laws result in tricky distinctions, and that's what case law is for.