Is laughing at someone mean and unkind and nasty and being a bully?

[HellyWorld]

For something they are sensitive or vulnerable about.

 

[icu1]

is not very nice

 

[Purpleflower]

Yes, although it's bullying if you are constantly harassing them with it.

 

[rom2014]

If the intent is evil then yes. If it is facetious then no.

 

[DeedeBartox]

yes, especially if they are in a gang and it's something that the victim is sensitive and weak about.