Say that I like the page "A" on Facebook. Then, I dislike it. Does Facebook still do its magic as if I still liked the page? For example, if the page was about bicycles, is there a chance that Facebook will display bicycle related ads to me? Or maybe is the information completely removed from Facebook?
Facebook has a policy of holding on to users’ data for a long time, even after they have deleted it. You can check the news for one such example relating to holding on to people’s images, even after they had deleted them. Also check out the Europe Vs Facebook page, where a guy is actively campaigning against Facebook’s misuse of peoples private data: