Perhaps explain in the about what you filter out? Along with what the bolding means?! Do you filter out anything else (like spaced/indented/monospace text/code, or even quoted text, which is often not written by the user?). Super thanks for this - interesting!

Turns out that there may have been some glitches in the way I was filtering lines beginning with >. For explanation of bolding see https://news.ycombinator.com/item?id=33755466. I didn't attempt to filter anything else out though filtering out code would probably help a little bit.