argumentum ad misericordiam (Appeal to Emotion -- literally, "argument from pity")

The argumentum ad misericordiam fallacy occurs when an arguer uses emotion in place of logic to convince someone to cave in from their stance.

Don't confuse this with properly infused pathos which can be used effectively when combined with logic and credibility. 

Example: Your honor, Andrew Goldstein should not be found guilty of parking illegally in a bus loading zone. He was sharing his vast knowledge of television reporting with a poor group of rag-tag journalism students at Prentice High School, going above and beyond the call of duty to do something good for the community. He's a really nice guy who everyone really likes. You wouldn't punish the poor guy for this, would you?

This may all be true and commendable; however, do they change the fact that he was parked illegally?

Example: 

It may be heartless to give this poor soul a parking ticket, but does that change the fact that the car is parked illegally?  In all honesty, the person who wrote this note is admitting to parking illegally which only makes the city's case airtight were this to proceed to court.