It is known, thanks to Gabber, that algebraic spaces are sheaves in the fpqc topology:

[Stacks project 03W8][1] 

Is the analogous statement for algebraic (Artin) stacks true? If not, is it true under some reasonable hypotheses?


  [1]: http://%5Ccite[%5Chref%7Bhttp://stacks.math.columbia.edu/tag/03W8%7D%7BTag%2003W8%7D]%7Bstacks-project%7D