It also showed that the habit harmed their grades. Social networking sites play a large role in shaping the political landscape. Meanwhile, dissenters worry that the dangers and wasted time far outweigh any benefit. They say that the sites offer access to educational materials and allow useful information to spread rapidly. This sparked the Arab Spring, a wave of revolutionary demonstrations across the Middle East and North Africa. They say the sites help spread false or dangerous information, and can even expose users to harm. Meanwhile, dissenters worry that the dangers and wasted time far outweigh any benefit. Supporters of social networking sites say that these online communities help increase communication with friends and family. In 2010, widespread anti-government protests began in Tunisia, a country in Africa. Sophomores and juniors only experienced a negative impact on their grade point averages when they used Facebook while studying. On social media, people can communicate with friends and strangers, do research, and share thoughts, photos, links, music and information about themselves. The site logs 4.5 billion "Likes" and over 300 million photo uploads every day. They say that the sites offer access to educational materials and allow useful information to spread rapidly. The revenue from social media ad sales is expected to reach $32.9 billion by the end of 2016. These ranged from someone using a login without permission to being threatened online or in person.