Some communities have agreed to share online — geneticists, for example, post DNA sequences at the GenBank repository, and astronomers are accustomed to accessing images of galaxies and stars from, say, the Sloan Digital Sky Survey, a telescope that has observed some 500 million objects — but these remain the exception, not the rule. Historically, scientists have objected to sharing for many reasons: it is a lot of work; until recently, good databases did not exist; grant funders were not pushing for sharing; it has been difficult to agree on standards for formatting data and the contextual information called metadata; and there is no agreed way to assign credit for data.
But the barriers are disappearing, in part because journals and funding agencies worldwide are encouraging scientists to make their data public.
Data-sharing: Everything on display
Richard Van Noorden
Nature 500, 243–245 (08 August 2013) http://dx.doi.org/10.1038/nj7461-243a