Financial blogger Barry Ritholtz says this well:
Many of the web's most important and integral websites are protesting seriously flawed legislation called SOPA.* It would greatly damage the linking structure of the internet, allowing companies to close down websites on flimsiest of premises. It would criminalize even pointing to any site that itself points to a site where there is a Copyright violation.**
Over the years, the copyright cartel — this includes Disney and other major content companies — have bought themselves a Congress. They prevented works that were scheduled to enter the public domain, as envisioned in the US Constitution, from doing so.
SOPA is the latest attempt to censor the public’s access to independent information and manipulate copyright laws. The new law works to their own benefit and the public’s detriment.
*There is another bill called PIPA in the Senate that internet experts say is equally bad.
**Alleged copyright violation. Copyright is a grey area so all you have to do is claim infringement to mess with an innocent party.