Below are a few reasons why you can not see all Facebook posts on Hashatit.com:
1) Facebook privacy settings are tight and only return to us “samplings” of Public Posts. To help with displaying #hashtag posts on Hashatit.com select “Public” from the drop down menu when posting on Facebook. For example, see below image:
Also, Facebook only supports hashtags internally and we can only return what Facebook gives us through their API search.
2) Facebook only allows some Public #Hashtags results to display on HashAtIt.com. Facebook does not allow Keywords or @mention search results on HashAtIt.com. HashAtIt.com ONLY returns Keywords and @Mentions results via Twitter, Youtube and Pinterest.
We hope in the future Facebook will give us access to ALL “Public” posts including Keywords and @mentions.