Social media allow people to communicate with others and this has increased online communication. There are numerous risks of attack on the use of internet and cyber criminals across the digital world. Cyber-crimes is the latest and the most sophisticated problem in the digital world. Cybercrime varies from computer fraud, unauthorized hacking, forgery, infringements of privacy, online gambling, propagation of harmful content, phishing, computer viruses, falsification of prostitution, theft, espionage, copyright infringement , financial crimes, sale of illegal articles, pornography, intellectual property crime, e-mail spoofing, cyber defamation and cyber stalking. The study was guided by the following objectives, to establish various forms of cybercrimes performed on social media, to examine the effects of cyber-crimes on the security of social media, to study the impact of cyber-crimes on social media security. The research population was used from the selected higher learning institutions and a sample size of 132 was used. Simple random sampling was used in sampling the respondents. A descriptive statistics analysis was done, comprising the generation of mean and standard deviation. SPSSv16.0 software was used to generate the mean and standard deviation. The findings show that many students share too much information through emails and social media which may pose threats to them. Most organization they have implemented multilayered security mechanisms information security may leak on the social sites. Cyber-bullying has spread widely especially are prone to the practice of cyber-bullying. Security attacks such as hacking, spoofing spamming cyber stalking Trojan, worms, viruses and exposure scams are common through social media, hence the ICT policy and government policy have address such issues. Higher learning institutions need to invest more resources in training students, awareness, research and development, IT security and social media crimes.