  Thirty years ago, Matsui and Satz proposed the $J/\psi$ destruction as a
signal of a Quark Gluon Plasma (QGP) formation, due to the Debye screening
between the pair c-cbar. At the light of the recent experimental data, I review
the different effects on $J/\psi$ production, from SPS to LHC energies,
distinguishing between Cold Nuclear Matter (CNM) and QGP effects. Different
possibilities and explanations for the available experimental data are
discussed. Model predictions for the arriving LHC data are also presented.
