Sometimes shareholders get to vote on it but usually with pinks and OTC it is approved and announced by the Board of Directors. It is usually a nasty surprise for anyone currently holding the stock.
The more shares that have been authorized and released makes it necessary to increase the ratio to bring the share structure back to a rational level. With 15 billion shares authorized and who only knows how many of those currently in the float I think something closer to 1000:1 will be required.