The report presents first results in a study on the opportunity to identify cyber threats in social networks with the help of experts’ knowledge and application of the scenario method. The process of validation is performed by two focus groups questionnaires-based surveys combined with experiments involving psycho-physiological monitoring. Study results conform with the hypothesis for users’ predisposition to hidden threats in known social network environment, related to social engineering. Additionally, correlated dynamic changes regarding studied users’ brain activity during regular surfing and entertainment activities have been also observed. The study provides a promising methodological framework for identification of obvious and hidden cyber threats in modern social networks, facilitated by already popular Web 2.0 technologies and emerging Web 3.0 solutions.