Half the time I have no idea what you guys are talking about

You double posted?

Protection ain't gonna save me from drowning in pussy

That's why people call me a sex God

Nah, I don't want to be accused off censorsing again.

(╯°□°)╯ ┻━┻

<3

(╯°□°)╯ ┻━┻

Because we're still testing it. We have to be more certain before doing it for more posts.

The watermark is a new feature we're trying out to see if it reduces repost

I noticed you

Or maybe you never posted that image? Yes. That's definitely it.
Don't try to stir trouble for nothing.

Yup. It seems like it's still up to the victim to pursue the matter legally.

Let's consider the pros/cons of using hash plus feature detection. Use a hash with low precision so the feature detection can decide if it's a repost. With this, reposts which look different are already left out. Now feature detection would be able to detect detailed images such as text e.g. memes.
So now we've slightly better accuracy with speed penalty e.g. ~2 seconds. But in the current system we let the user do the feature detection part but with a higher hash precision. Also would be more work to implement feature detection.

When you've actually tried it yourself you'll understand why there are so few good solution. The only one I know of is TinEye. Just try searching this post's image in TinEye or Google Image Search.

The solution you recommended is a more accurate algorithm but it's also very much slower. The fact that it doesn't have indexing already makes it impractical. The second problem is the nature of our content.
1. Content are often presented differently e.g. the same text can appear in a tweet, tumblr post, or on a photo
2. Details of the content matter. Take for example a tumblr post or a generated meme. The difference is either too large or too small to be considered a repost. That means either lots of false positive or false negative. Of course this is still more accurate than the implemented algorithm, but not enough to justify the drawbacks.
3. We can no longer filter or index images and the speed of the algorithm is O(n). Take for example 300 posts a day * 7 days = 2100. Optimistically (very) each comparison is 0.1 seconds =210 seconds for each user upload.
So yes we do have a better system. We can't afford to spend months or years developing a perfect repost detection.

@tylerchu can you point me to a page where I can see how it work.

No

People are often led by their emotion. Appealing to them rationally does not work as seen in recent prolific events. Users blatantly wrecked havoc despite warnings from their peers.

We deal with every case of bullying/harassment that comes to our attention. The lack of visible evidence on your part does not mean a lack of action on our part.
More importantly, you have to understand that the Internet is free for all. Cyber bullying/harassment is a difficult problem that even big companies like Facebook cannot eliminate. We believe that as the community grows bigger, such conflicts will be reduced and we (you and me) will be able to respond faster to threats.

Me too