Tweets streamed from outside bounding box?



I am using the Streaming api as I want to get all tweets from my local town.

I have the stream working and I have set my location coordinates as specified in the documentation, 2 pairs of lat/long coordinates with the southwest coordinate first. (It also took me a while to realise that the api likes the longitude to appear first in the lat/long pair. )

The problem I have is that tweets are being returned from way outside my bounding box? Which makes me think that maybe something is wrong?

Should this be happening?

Many thanks,