Q: How can I personally discover if there are previous posts of an image?

A: KarmaDecay.com is a reverse image search engine specifically for Reddit.

     It was described in an online article as the "TinEye for the Alien Guy". Upload an

     image, or paste it's URL, and Karma Decay will search for previous links and

     comments on Reddit for that image. The bookmarklet and add-ons integrate

     Karma Decay into Reddit.

 

Q: Does the bot find every previous post?

A: No. It covers only the top 1000 posts from the top 10 picture subreddits.

     Also, every implementation for finding similar images is imperfect, so the bot

     tries to only use matches when it has a high level of confidence, ignoring other

     potential matches that it isn't as sure about. 

 

Q: Does the bot downvote reposts or upvote other posts?

A: No. The bot does not upvote or downvote any posts or comments.  You can verify

     this by visiting the liked and disliked pages on the bot's user page.

 

Q: Why are you ignoring the reddiquette guidelines about not complaining about reposts?

A: The bot is not complaining. It is providing a quick and easy way to discover

     valuable information in previous comments.  The wording used by the bot was

     carefully chosen so as to be as friendly as possible.

 

Q: Why are you doing this?

A: For the joy of programming and creating something useful. The best comments

     on Reddit are those that inform. By linking to previous Reddit comments, the bot is

     linking to a treasure of valuable vote-filtered information. For example Reddit comments

     will often tell you information like: is it fake, what is the story behind the image, who is

     the original creator, and more.

 

Q: Won't people downvote my post if they see that it is a repost?

A: Are you posting an image for the community or for karma points? Hopefully you are

     posting for the community and view karma points not as a game to win, but as a way

     to measure what the community values. Similarly, the bot is posting information for

     the community. If the information it provides does influence the votes of a few members,

     then the information it provided was valuable to them.

 

Q: Aren't you spamming?

A: The bot is linking to Reddit posts within Reddit, and does so without bias. Reddit

     posts already have a "related" tab with links that are generated automatically. The bot

     is providing a similar automatic service, but with a more specific focus.

 

Q: Is it OK to run bots on Reddit?

A: Mods and admins are free to ban any user account as they see fit. Common sense

     would say that useful bots are acceptable, annoying bots are not. On Reddit, its pretty

     easy to distinguish between the two by looking at the bot's karma. There are a few well

     known bots running on Reddit that seem to be well accepted by the community. It's even

     been claimed that the admins have assisted at least one bot writer.

 

Q: Didn't this bot say something snarky and rude in the past?

A: A previous version of the bot began with the line "This looks familiar". With hindsight,

     it's clear why some people viewed those words as being snarky, but that was not the

     intended meaning. The words were only a reflection of the nature of the bot's algorithm.

     The phrase "looks familiar" was a short way of saying "this image seems to have a similar

     appearance to previous other images in my database".

 

Q: I still think that you are an arrogant repost-complaining piece of &@!+ and you

     should stop violating the reddiquette!!!!

A: Well that really isn't a question, but... Firstly, the content being posted is not violating

     the reddiquette. No criticism or complaint is occurring. The messages have useful

     information. All that remains is for the community to vote on how useful it is.

     Secondly, did you know that the reddiquette was not written by the admins? The reddiquette

     is simply a set of opinions from more senior redditors. The guideline regarding repost-complaints

     was only added in July 2011 and it has already been revised since. So please try to avoid becoming

     overly militant about any particular item in the reddiquette.