The effect Speaker 2 is most likely trying to achieve with this argument is:
making their opposition seem absurd or flawed to make their position seem more rational by comparison.
By bringing up the issue of overdue library late fees in the context of oppressive laws and violent crime, Speaker 2 may be attempting to highlight what they perceive as a disconnect or absurdity in the comparison made by Speaker 1, therefore positioning their own argument as more reasonable or valid in contrast.