Europe's top court, the Court of Justice of the European Union (CJEU), has struck down the 15-year-old Safe Harbour agreement that allowed the free flow of information between the US and EU. The most significant repercussion of this ruling is that American companies, such as Facebook, Google, and Twitter, may not be allowed to send user data from Europe back to the US. It's important to note that the CJEU's ruling (PDF) will not immediately prevent US companies from sending data back to the motherland. Rather, the courts in each EU member state can now rule that the Safe Harbour agreement is illegal in their country.