  Hidden sectors with light extra U(1) gauge bosons, so-called hidden photons,
recently received much interest as natural feature of beyond standard model
scenarios like string theory and SUSY and because of their possible connection
to dark matter. This paper presents limits on hidden photons from past electron
beam dump experiments including two new limits from experiments at KEK and
Orsay. Additionally, various hidden sector models containing both a hidden
photon and a dark matter candidate are discussed with respect to their
viability and potential signatures in direct detection.
