Is it illegal for an employer to clock you in and out for your shift?

ok my question is can a employer clock you in or out for your shift.see the place i was just working at started clocking people in and out depending on where they worked in the plant.there were times people got clocked in late and lost sum pay because of it.and then there were times that we got got clocked out before the end of our shift.i dont think this is right at all.but if it is illegal for them to do this does anyone have a site for me to check out about it or even a place to report this?i live in pa if that is any hel thank you for your time.