random item in my trash, has odd title. what is it?

[ceezy3000]

so after freezing and freezing i finally logged in my computer. i just noiced there is something in my trash. its a folder titled Database. and inside the folder it says Database.sqlite3. WTF is this? im thinking its something to do with sql or something right? but i dont have any apps like that.what is this?

 

[angelwatt]

I have that file. It's originally located at:
~/Library/PubSub/Database/

See this thread for more info.
or
this thread at Apple support.