Educators have a duty to encourage virtue in their students, or at the very least never to encourage vice.

Instead of presenting an example about a thief and unintentionally normalizing robbery, why not substitute an example that will encourage your students to good deeds?

For example, "A benefactor wants to distribute food to families in a neighborhood that recently experienced a natural disaster. In order for the benefactor to remain anonymous he must not drop off food baskets to two consecutive houses. If each house contains the given number of family members, what's the maximum number of people this good man can feed?"