Not sure who told you that. Most employees with either have options (which can become shares, but aren't) or Restricted Stock Units (RSU's) which are useless till vested.

Either way their holding will be miniscule, even in aggregate, compared to other shareholders. Even if it wasn't miniscule, they would still need to organise, maybe form some sort of coalition, or "union", in order to leverage their collective voting power against other large, unified, shareholders.