Who said there will be 15,000 protesters at the RNC?

You can't miss it. It's in every story reported in Tampa regarding the RNC.

Tampa Bay Times reporter Kim Wilmath began her Monday above the fold story like this:

They've painted their posters and planned their marches.

Now the question is, where are the 15,000 protesters expected to come and shake their fists at the Republican National Convention going to stay?

The Tampa Tribune's Ray Reyes and Kevin Wiatrowski cite the same figure in their front page story regarding the concerns about tropical storm/hurricane Isaac possibly hitting Tampa.

But really, does anybody know how many protesters will be at the RNC? And how did the figure of 15,000 become the go-to number?

This article appears in Aug 23-29, 2012.