From the site of the Stop Sopa campaign:
What is “Ireland’s SOPA”?
SOPA is the name of a piece of US legislation, the Stop Online Piracy Act, recently proposed in the US. It caused an Internet-wide outcry due to its far-reaching implications; way beyond simply closing access to outlaw file sharing websites, it would have enabled law enforcement to block access to entire internet domains due to infringing material posted on a single blog or webpage.
A similar proposal is about to become law in Ireland. And while 7 million Americans contacted their representatives to say No to SOPA in the US, Irish citizens will not get that chance because the new law in Ireland is not being voted on in the Oireachtas.
Instead, the law is being enacted by ministerial order. This new law will give music and movie companies the legal leverage to force Irish ISPs like UPC, Eircom and mobile networks to block access to sites suspected of having copyrighted material on them. It also means judges can order ISPs to block access to sites like YouTube, Facebook and Twitter where an individual user from anywhere in the world has shared infringing material.