1) Univision streams it live HD .. it is free with excellent quality but unfortunately spanish commentary.. if you have no other options :) It wont stream semi/finals though.

http://deportesenvivo.univision.com/

2) Or Canadian channel cbc streams live for canada only. If you are in US, use 'Hola proxy plugin" or use some similar proxy for canada :)

http://www.cbc.ca/sports-content/soccer/brazil2014/

3) There are some online streaming services - paid. Use that. Or smart way is to use "one month of free trial" subscription, and after one month cancel the subscription to avoid payment..

one such service is offerred by Aero..

https://aereo.com/channels

4) Or use p2p streaming utilities e.g Sopcast (http://www.sopcast.com/ )..

5) Or go to your neighbor's home with 6 packs and some chips to watch games at his cable tv :)