I looked into this a couple years ago when it was the "Next Big Thing" and there were several vendors selling curation software and systems.
They all sited "Huffington Post" and other huge sites with "curated" content. This was the key to the whole marketing speel, "These big sites are doing the same thing and raking in millions and so can you!"
The movement kinda died when people were getting sued for using other peoples content without their permission. I think it is now relegated to the "black hatters" who can evade the law a bit and don't care about copyright.
All the ones I was looking into have "For Sale" on their domains for quite awhile now. It is a great idea, but there is a lot more legally to it than just putting other peoples stuff on your site hoping to get more traffic.
Even if you think you are doing it "legally", most don't take the time to check with a real lawyer first to make sure it IS legal to do. The thought of it being "easier to ask forgiveness than ask permission" comes to mind. That thought fails to hold up in court though...it isn't a problem until you are caught.
The thing they didn't mention is these large sites have legal deals for licensing this content with the intellectual property owners. Even if there is no money traded, the legal licensing is the key that keeps you out of jail or the poor house from a lawsuit. They got permission first to put the content on their site. Then there is the thing too of "I am on Huffington Post! So what if they didn't have permission - I am famous now! Oh, I am suing you for 10 million since you stole my stuff, now I will be famous AND rich!"
It is one thing to put links to others peoples interesting content or small quotes with citing in your own original blog post than it is to publish "THE" content or even large snippets with comments on your site. The site with the original content may have provisions in their TOS like "no copying, reproducing, or distributing without explicit written permission" (most do to prevent someone from using their exclusive content) you could be violating their copyright and then be sued for copyright infringement. You have no defense at all if their content IS on your site and you have no legal document to prove you have permission to do so.
Some site owners are very anal about their stuff.
This was, again, something that sounded really good on the surface, but once you dug into it was not so appetizing. I try to not be sued or in trouble with the law. Just one of my quirks....I don't look good in orange...So my advice is to check with a real copyright lawyer to make sure you are not already in trouble with what you are doing.
You could also check the site you are curating content from and see if it has one of those "do not copy...blah...blah" in their TOS. If they do then it is an "OH, CRAP!!" moment.