"It's true that someone can cheat on the numbers they show on their board. This has happenned sometimes and i have removed the ones that were spotted."
Your number 5 site says 26 million posts. I see less than a million.
"i try to serve people looking for active boards about a certain topic. If someone looks for a board to discuss his brand new mazda rx7, i daresay my site can provide him with some."
This, I would agree is your most important function, and for that I don't even see a need for a sham post count to be displayed at all.