Many of us here frequently use MathJax, whether for this site or another site on the SE Network.
Recently SE added support for tables, but ignored the needs of the TeX community, who wish to be able to type TeX symbols/formulas/etc. as well.
This is the feature request on Meta.SE, to support MathJax in tables.
Here's some network-wide examples where such support would be needed (please add anymore if you're aware of any!):