I serve as an editor for several scientific journals. Basically I assess submitted manuscripts at a general level to see if the work is appropriate for the journal. I also make sure the work appears valid at a most basic level. If the manuscripts meet these requirements, I recruit a number of expert reviewers to rigorously assess the data and conclusions of the paper using criteria specific to the journal. (There is significant overlap in criteria between journals, but each journal has some specific issues or requirements.) Once the reviews come in, I have to integrate the reviewer assessments as well as my own and reach a decision on the paper: accept, revise, reject, etc.
Today I was looking at my new assignments and saw a paper that based on the title and abstract was appropriate for the journal. I quickly skimmed through the paper, which looked a little light, but seemed to relate some useful new information. So I went looking for some reviewers (I try not to use the same reviewers, because we are all busy and it's important to spread the workload around). One of the easiest way to identify reviewers is through a simple pubmed search. Enter a couple of relevant keywords related to the paper and voila instant potential reviewers.
Except today. I enter two obvious keywords, hit return, and get ~100 articles. The first of which is on the same topic as the paper I'm handling (I can tell from the title). Well that sucks, but it happens. Separate groups work on similar problems. Hopefully there will be enough differences between the papers that the one I have can still move forward.
Oh wait, the published paper is by the same group! FUCKITALL. I looked through the just published paper and see that there is minor difference, but the papers are essentially the same. On the plus side, there was an additional data set included to a figure in the paper in my hand. On the negative side, there was an identical figure. (The word you are looking for is plagiarism, and yes you can plagiarize yourself.)
This pisses me off, because authors agree when they are submitting papers that their work is not being considered elsewhere. For the authors, they can maximize the chance of getting published. But the authors are wasting everyone else's time. Half of the reviewers are wasting their time assessing the rigor of a paper that is not and will not be publishable. Add in the waste of time on the editors and journal associated staff and it is bad practice.