is this a problem?

if you allow the trolley to continue on its course some say this is akin to allowing the people to die but to switch the tracks in this case would be seen as active act of killing.  

however, the majority of people feel it is permissible to switch the tracks in order to maximize the number of lives saved.  this seems to lend support to the ethical theory of Utilitarianism which argues one should choose actions that maximize utility (the greatest good for the greatest number of people).

but the problem does not end here, a variation of the trolley problem was then introduced to challenge this Utilitarian interpretation of the choice to switch the tracks.  here, instead of switching the tracks to prevent the trolley from killing the three, you can push an innocent bystander onto the tracks who is large enough to stop the trolley.  however, this will kill the innocent bystander.

given this innocent bystander scenario, most of the same people who thought it was permissible to switch the tracks to redirect the trolley to kill the one will argue that it is impermissible to push the bystander onto the tracks.  

this, according to some philosophers, shows a stronger difference between killing and let die. to switch the tracks is more akin in this interpretation to letting die and pushing the innocent bystander to killing