  Hidden sectors with light extra U(1) gauge bosons, so-called hidden photons,
have recently attracted some attention because they are a common feature of
physics beyond the Standard Model like string theory and supersymmetry and
additionally are phenomenologically of great interest regarding recent
astrophysical observations. The hidden photon is already constrained by various
laboratory experiments and presently searched for in running as well as
upcoming experiments. We summarize the current status of limits on hidden
photons from past electron beam dump experiments including two new limits from
such experiments at the High Energy Accelerator Research Organization in Japan
(KEK) and the Laboratoire de l'accelerateur lineaire (LAL, Orsay) that have so
far not been considered. All our limits take into account the experimental
acceptances obtained from Monte Carlo simulations.
