1. The document discusses issues around detecting spam and identifying fake profiles on social networks like Facebook, Twitter, and Sina Weibo.
2. It notes that 20-40% of profiles on social networks could be fake, and identifies challenges in differentiating fake from legitimate profiles due to limited publicly available user data and varying privacy policies across networks.
3. The paper aims to identify approaches for detecting fake profiles using only the minimal publicly available data on each network, and to evaluate their accuracy compared to existing methods using more extensive data.