how can they become risky to humans?
They can transmit zoonotic disease to humans.
Exotic pet
 they still have the potential to transmit zoonotic disease. 
from where does the word 'wolf' come from? From Old English. what do they prey on? Large sized wild herbivorous hoofed mammals. what does it represent in mythology? According to the Pawnee creation myth, the wolf was the first animal brought to Earth can we keep them as pets? Yes, they are sometimes kept as exotic pets. can you name some other animals that are kept as exotic? Cottontop tamarins, baboons, chimpanzees, Diana monkeys, lemurs, and gibbons. is it legal to keep them? Nine states ban the keeping of non-human primates, but no federal law regulates ownership.
wiki:13933903
Exotic pet [SEP] Primates
Although the breeding population has been largely isolated from wild populations outside the US, they still have the potential to transmit zoonotic disease. There is a considerable risk of monkey B virus from rhesus macaques. Research workers have died from this disease contracted from non-human primate research subjects. Additionally, there is considerable risk to the non-human primate pet through transmission of human disease. One such example is herpes simplex virus, which can be deadly to certain smaller monkeys.