This research is dedicated to one of the significant problems connected with purchasing online: consumers’ personal data security. The purpose of the paper is to present the results of a study of an incident of a personal data breach from the Morele.net online store that occurred in Poland. The current gap in the literature is the lack of research done among consumers who suffered from a data breach. Data from 826 people affected by this incident were collected and used for drawing conclusions regarding the changes that took place after the incident. The data obtained are both qualitative and quantitative. The data set was analyzed using the IBM SPSS software package. The evolution in consumers’ trust towards the store was studied and results reveal that it has strongly decreased, although this did not influence consumers’ attitudes towards online shopping in general. The main finding of the research is that one out of three affected consumers will discontinue online shopping on Morele.net; however, they will not tend to change their online shopping behavior in general—they will just purchase in other online stores. Moreover, even though consumers were disappointed, and many were considering no longer purchasing from this site, the store still had significant opportunities to regain consumers’ trust and save its competitiveness in the market. The results suggest several improvements that should help online stores stay secure and trustworthy for their consumers. It was revealed that consumers had not previously been greatly concerned about their data being protected by the store; this incident, however, had changed this fact, and now consumers had become much more conscious about providing any of their data to any website.