http://www.pcninja.com : I know first hand how hard it can be to remove Security Shield. If you need an expert to remove Security Shield for you we recommend http://www.pcninja.com. They are great at what they do and based in the United States.
Tee Support: This company is cheaper than the above and does do a good job. However they are not based in the United States. That is why they are cheaper. If you do not mind a little language barrier we do recommend them as a cheaper but not better repair company.