Obamacare is an easy one, as the government is leveraging the tax code to mandate that citizens obtain health insurance. Exacerbated somewhat by the idea that the health insurance is now a government-supplied good, and that they will have an effect on controlling its prices and such.
This was enabled by a couple of Supreme Cases under FDR - which, while I'm usually wary of attributing SCOTUS actions to the president of the time, FDR was responsible for the appointment of EIGHT Supreme Court Justices, stacking the deck - Wickard v. Filburn eroded all libertarian meaning of the Commerce Clause. Helvering v. Davis eroded the concept of personal economic liberty, in that since its interpretation, the government is allowed to take money from you and give it to others, as part of the New Deal push for Social Security.
These two cases are also considered, generally, to be some of the worst decisions by the Supreme Court, and both of which led to vast expansion in government powers. As those expansions were used primarily to take away from the citizenry, they subsequently eroded civil liberties.
The commerce clause is now what is used to allow the federal government to arrest California medical marijuana proprietors, even though it is perfectly legal in the state of California, which means that the impact of the clause has effectively eliminated the idea of states' rights. If the states have no sovereign rights from the federal government, then you can rest assured that the people don't either.