Social Security Taxes are 12% paid by you which is matched by your employer. Medicare is the other 3%, also matched by your employer for a total FICA tax of 15% paid by you which is matched by your employer.
Social Security is not cheap, especially when compared to other retirement plans and disability insurance is the reason. We need to figure out a way to insure folks against true disabilities without making a successful DIB claim an early retirement jack-pot.
Becoming disabled should be a bad thing.
Edit: Rates wrong - see below.
No. SS is split between you and your employer. You currently pay 4.2%.
Edit: I posted this before i saw your edit.
The normal rate is 12.4%, which is split by the employee and employer. The bottom line is that it is a tax on the employee. While the employer pays half, it is a payroll cost more than an actual tax to the employer. The Medicare rate is 2.9% and is split the same way. So while your employer pays half, it really is a combined 15.3% tax on you, the employee. Just ask anyone who is self-employed since they pay the full 15.3%.