Dù Zǐténg - the Chinese characters "杜紫藤" form a very refined name that could belong to a poet (紫藤 is the name for the Wisteria sinensis flower), but it is homophonous with the word 肚子疼 which means "stomachache."
Jìyuàn - the names of technical schools which end in 技術學院 jìshù xuéyuàn are often shortened to 技院 'jìyuàn' which has the same pronunciation as 妓院 which means a brothel.