Why is the local council giving me a smaller wheelie bin?

We got a letter through the door on Tuesday saying that we're getting a smaller bin instead of our old larger one which is to be removed as part of their new refuge rules and that instead of our rubbish getting uplifted weekly it will now be fortnightly! won't this encourage rats and other vermin? To top it all off they said if I leave any bags or if my bins looks to be overflowing then they won't lift it and I can get a fine of �5,000 for fly-tipping! I'm so enraged because these PC rules are mad and will only encourage fly-tippers to dump their rubbish. Other people I know leave black bags on the street and their bins are overflowing from one week so I dread to think what two weeks of rubbish will be like...