In the scientific community, there is a debate available about the pros and cons of the preprint server Arxiv. Critics are arguing, that arxiv isn't a peer reviewed journal in the classical sense which is equal to a low quality standard.
To verify or reject the thesis it makes sense to judge about the existing content at Arxiv. Suppose somebody is interested in reading something about Fuzzy logic for diet composition, about the Dean drive (which is some sort of antigravity) and about telepathy which is a psi phenomena known from the Ghost busters film. All these information are available at Arxiv:
Computation of Diet Composition for Patients Suffering from Kidney and Urinary Tract Diseases with the Fuzzy Genetic System arXiv:1306.5960
Experimental Null Test of a Mach Effect Thruster, arXiv:1301.6178
New Resonant Bivacuum Mediated Interaction, as a Possible Explanation of Psi Phenomena arXiv:physics/0003044
So we can say, that the arxiv submission pipeline has a strict quality control system which makes it unlikely that fringe content or non scientific knowledge is hosted on the website.