This work aims to analyze the evolution of social networks users’ behavior on the internet regarding to the custody and recall of photographs, and how knowledge organization has been introduced in a natural and progressive way, by platforms and applicatives, in the day to day of users of social networks in the internet. Making the photo sharing experience faster, simpler and more attractive.Through the observation of how the sharing, the guarding and the organization of photographs in these environments are given, we intended to record and contribute to the reflection on the impacts on personal and collective memory in a society that has been using social networks as a place for personal photographs custody and records of their daily activities and events.

A bibliographic review has been carried out on how some Knowledge Organization instruments have been used in social networks on the internet for photo storage and retrieval. It was also made a historical and analytical study of the use, sharing and custody of photographs in social networks on the Internet, such as flickr, tumblr, facebook, instagram, snapchat and pinterest, as well as how it impacts on personal and collective memory. In order to understand and analyze the behavior of the users of social networks, we applied a closed questionnaire online asking about the experience and perspectives of the respondent with respect to the use and custody of photographs on the internet.

Preliminary results point to a promising backdrop for pictures after web 2.0 revolution and with the resources that the web 3.0 will have to offer. The main reason man has invested so much improving photography throughout history is the desire to record moments, and these records are only justified if they can be accessed. We could observe that platforms and applicatives of social networks has been using knowledge organization  instruments to meet the demand of the photographs recovery presented by the users. Introducing, thus, knowledge organization in the day to day of users of social networks in the internet in a natural and progressive way.

With the constant increase of the speed of connection and the availability of storage space in the web, the amount of photos uploaded and shared has increased exponentially. Thus, it becomes increasingly difficult to locate a photograph without the aid of tools. Indexing practice was one of the tools used. And, thanks to Folksonomia, defined by GONZÁLEZ (2011) as a cooperative indexing that adopts words to represent information in a spontaneous and free way, quickly became popular. Because, by allowing the free classification of information by the public, it guarantees that the content will be naturally related to the words that the users believe to have connection with them.That is, the words that are most likely to be used when searching for certain content. Freeing the moderator of the platform, or the applicative, from the obligation to know all kind of matters deeply.

The use of hashtags, after the success in twitter, as a mechanism for recalling photos in instagram was so well accepted by users that it started to be used in other social networks even without the hyperlink feature. Started to integrate the vocabulary and the way the Internet user communicates.The indexing success, through tags, hashtags and pins, can be attributed to the natural vocation of the human being to classify and to the evolutionary needs of communicating and being part of a group.

The questionnaire has shown that the same promising scenario for photo diffusion and retrieval can be very dangerous when it comes to preserving memory. Many users have already lost photographic records due to the extinction of social networks (photologs, orkut). And even with awareness of the risks, they continue to entrust their photographs storage to social networks. There are very few people who still do back-ups or even reveal photos. In addition, the number of photographs that were not produced as a record but rather as messages has increased in social networks. There is a change in the value and meaning of the photographs. The photography feature as a communication language recently gained prominence with the one feature launched by the Snapchat application. In it, the user programs how long the picture will be available after viewed by the recipient. As a result, in this context photography only communicates and it does not serve as memory record. And it seems that this way of communicating will be increasingly explored, as several social networks have adopted the "stories" inspired by Snapchat.

Therefore, considering the large volume of photographs on social networks on the internet, and the increasing number of photographs that are intentionally lost every day, we see a change in the meaning of photography on the internet. Increasingly used for communication and less as a registry of the present to be revisited in the future. In this context, the photographs treatment that we desire to preserve must be more cautious, so that they do not get lost among other photos.

Indexing is an important tool for retrieving photographs by users of social networks and, in a way, assists in the maintenance of personal and collective memory as long as more accurate technologies for retrieving image content on the internet are not developed. Until then, it would be interesting to guide and make users aware of how indexation can be a tool for the present, helping communication, representation and organization, and for the future, recovering and giving access to photographs and memories.