What´s happend with the Safe Harbor?

The Safe Harbor is a list of American companies that Europe considers they follow as following the Directive of Data Protection. The European enterprises and users can used to be able to (remember, it happened in the past, so you don't say, "can" you say, "used to be able to" [be able to is a way to say, "could" that sounds better for this more serious topic]) transfer personal dates (I think you mean data, but if you mean, "fechas," disregard this as you are correct) with these companies, but after the European Court of Justice´s sentence in October, the data transfer between American companies and Europe is became (yes, it is illegal now, but the point of this sentence is to say that it became illegal in the past, so you want to say, "became") illegal (you forgot one 'l'). Services like Google, Facebook or or (not Facebook o Dropbox, Facebook y Dropbox) Dropbox can´t be used for storing personal data in Europe, and this is a serious problem because a lot of European companies use them every day and they can´t leave it them, (it is one, them is multiple) as this (you have to add, "as this," because you have to express complete thoughts and, "would be a hard job..." doesn't specify what would be a hard job) would be a hard job and too expensive.

You did a great job on this! You picked a difficult topic to write on and did not have a lot of mistakes at all.