This via Wikipedia today:
SOPA and PIPA would put the burden on website owners to police user-contributed material and call for the unnecessary blocking of entire sites. Small sites won't have sufficient resources to defend themselves. Big media companies may seek to cut off funding sources for their foreign competitors, even if copyright isn't being infringed. Foreign sites will be blacklisted, which means they won't show up in major search engines. SOPA and PIPA would build a framework for future restrictions and suppression.
In a world in which politicians regulate the Internet based on the influence of big money, Wikipedia — and sites like it — cannot survive.
Congress says it's trying to protect the rights of copyright owners, but the "cure" that SOPA and PIPA represent is worse than the disease. SOPA and PIPA are not the answer: they would fatally damage the free and open Internet.As noted above, SOPA and PIPA would impose large cost on existing firms that could some companies out of the market. In addition, these laws could act as a barrier to entry for new firms in the user-content realm. Is this a good or bad thing? It comes down to one's beliefs on the following question? Does the freedom currently enjoyed on the internet in the United States have a net positive or negative externality for society?