TWITTER4J - Filter tweets by location: tweets outside defined area

Question

Developing an android app, using twitter4j. I'm filtering tweets by location:

public void filterDataWithNewUserLocation(double latitude, double longitude) {
    FilterQuery filterQuery = new FilterQuery();
    //double[][] locations = {{12.6340, 45.7828}, {13.6340, 46.7828}}; // SW NE
    double[][] locations = {
            {longitude-0.3, latitude-0.3},
            {longitude+0.3, latitude+0.3}};
    filterQuery.locations(locations);
    twitterStream.filter(filterQuery);
}

and I'm obtaining tweets inside AND ALSO outside the area I defined. Where I'm wrong?