For instance, the rider may deliver the medicine to the wrong person. Let's assume that you ordered medicine for your granny and you were not home at the delivery time. So, your son, who is a kid, received the parcel. Now, he may either take the drug himself or forget to inform.  Take another example. The rider may ship your parcel to your neighbour who is also waiting for her medicines. Imagine if she takes the medicines in a hurry without checking and experiences adverse effects. Even, sometimes, the riders leave the parcel in the mailbox that increases the chances of drug theft.