Hamsters are Small
An aggressive hamster is not going to do much harm to a human. A little nip may hurt a tiny bit. But hamsters are so small that it should be quite insignificant. If it's that bothersome, it's nothing a pair of gloves can't solve.
Aggressiveness is Not Always Permanent
We've successfully tamed three hamsters labeled as aggressive. All it took was a little time and lots of love. Another of our hamsters was labeled as aggressive. But once we got her home, she was completely different. She's actually the tamest and friendliest of all of the hamsters we've rescued.
Hamsters Live in Cages
Because hamsters are not going to be free roaming the house, it is not likely that aggressiveness will be a huge problem. Some hamsters do like to come out and play in a designated, properly secured area. But even during these times, it is not likely that an aggressive hamster is going to be a threat. Wear gloves during feeding and handling times, as well as during cage cleanings if you're worried about the boxing and nipping.
Aggressive Animals Still Have Feelings and Needs
Usually aggressive animals are that way due to mistreatment or health conditions. That doesn't mean they don't deserve a loving home too. They still need to eat, have access to fresh water, and live in a comfortable and safe environment. Sometimes providing those simple things is all it takes to tame a hamster. Sometimes it takes more. Sometimes they remain aggressive. Either way, they are still living, breathing creatures with feelings and needs.
Talk to your local animal rescues and shelters (and do the proper research on care) if you are interested in learning more about adopting aggressive hamsters.