A more appropriate plugin for the OP's question is Hypothes.is. They're open source, non-profit and have raised over $1.5 million. They have about 7,300 users according to the chrome webstore:
https://chrome.google.com/webstore/detail/hypothesis-web-pdf...
There are quite a few efforts out there. Someone has already mentioned rbutr (actually my personal project) - you can view it in action without the plugin by just adding rbutr.com/ to the front of any URL, eg: http://rbutr.com/http://www.realfarmacy.com/johns-hopkins-sc...
However rbutr isn't really what you've described here. What you've described is either
Oh, also, Hypothes.is had previously put together this spreadsheet on Google Docs which lists all of the previous efforts to make web annotation applications. It hasn't been kept up to date though so I keep a local one up to date now, just in case this is ever lost: https://docs.google.com/spreadsheet/ccc?key=0Aujm_HldNh4WdHJ...
Anyone who applies for the current round and makes it in should know that there are more places to live in Chile than Santiago! Come live down in Pucón with us. We've got a live Volcano in our backyard! Best place to go if your business is tourism focused, for sure :)
So far we are getting very promising numbers. The main difference betwen us and all of the annotation services which have come before us (around 50 on last count, thanks to Hypothes.is), is that we are page level. We connect one URL to another. It is so simple your grandmother could probably do it. The previous versions were all line-level, meaning that you had to highlight text and then write your comment, or connect to another page etc. It was overwhelming and confusing. rbutr requires you to press two button, small descriptive comment and tag. You don't need to be an expert on the subject matter or anything. You just connect the two authors who claim to know about it to one another...
It is all manual I am afraid. We are reaching out to Skeptic communities right now in an effort to get the ball rolling and get as many rebuttals added as possible. We're getting amazingly positive support from the Reddit skeptical community (which is where this post came from), and I will be at the Amazing Meeting in July, talking to skeptic community leaders from all over the world.
But of course, everyone and anyone can add rebuttals, so please, feel free to add any whenever you happen across one :)
Zakharov, I'm really sorry it didn't work for you. It is clear that this happens to a small percentage of the people because we occasionally get messed up submission coming through from the tutorial (which in theory should all be the same).
As of yet though, we are unable to replicate the problems. If you could provide some details of your OS and browser, and exactly what happened, I would appreciate it.
Because normally, copy and pasting a URL in to the rebuttal place actually isn't allowed at all. So something has gone very wrong! Also, the Tag box is indeed normally editable (after addition of the first tag).
So I just wanted to let you know, that there is a bug causing those faults, and we haven't identified what is causing that bug yet...
We are building a website version of the 'Request a rebuttal' and 'Submit rebuttal' functions, so you don't need to install the plugin in order to participate (or view the material being generated either, of course, as is already the case).
However, in order to use these functions, there needs to be a user account for it. Otherwise people might 'test' things out and create nonsense links. Repeatedly. User accounts are a necessary filter in order to ensure we aren't inundated with testing clicks, and to provide quality control, and all the other things which follow from having registered users.
Most every page these days requires registration, so I don't think this is particularly odd.
Though we are now looking at creating a membership-free installation which allows you to complete our tutorial - and if we can, I would like it if that un-registered version could also deliver rebuttal alerts... So feedback is working. Now it will just take time to implement it all!
While it will no doubt get used as 'auto research for lazy people', the implications of success for this project are much bigger than just that. Providing automatic skepticism for the average person is unheard of, but with a wide enough net cast by an active community, and wide uptake by common users, that is exactly what can come of it.
Definitely the chicken-egg problem is our main hurdle, but we are working on that by turning this project in to something more than just the plugin. We are also focusing on connecting with the most active communities who already engage in exactly the sort of activity which we need - the Skeptic community is exactly that community. So we are walking away from chickens and eggs, and going straight after the seeds.
So it says about 10,300 active plugin users.
A more appropriate plugin for the OP's question is Hypothes.is. They're open source, non-profit and have raised over $1.5 million. They have about 7,300 users according to the chrome webstore: https://chrome.google.com/webstore/detail/hypothesis-web-pdf...