In this talk, we will present some concepts and motivate individuals privacy problem in a world where people are more and more connected, while organizations and individuals publish a lot of information over the web. We will present research achievements and on-going data privacy problems we are investigating at the Database and Systems Laboratory of UFC. We will discuss mainly the subjects we are interested in as location-based data privacy and correlated sensitivity for differential privacy. We will explore our approach for data correlation identification in a data set and its impact on noise perturbation in a differential privacy mechanism. Finally, we will conclude with some opened issues.