First I would like to talk about some of the barriers:

1- the students might get distracted by the ads that shows up and then you might loose their attention.

2-they may get some spam followers or suspicion accounts.

3-the algorithm of some social media networks would also get them to unwanted links.

What I suggest is that you get your students to work on learning management system (LMS) that that you prepare and upload all the material they need for learning and enjoy the collaboration and networking they need to achieve the learning outcomes you hope for.

most students use it for personal reasons and rarely for educational or learning purposes

you can refare this articals Article The role of modern media technology in improving collaborati...

Good points, dear Amal Alaradah and Mohammed Habes

Another barrier is susceptibility of students and teachers to demotivating remarks in addition to privacy violation, which can result in severe emotional stress. In one of our discussions in a University of New South Wales course, a report was given of a teacher who gave an assignment that required students to post their work to Twitter for peer assessment. Many comments came from persons who were neither members of the class nor students of the institution. Some of the comments some of the students got were insulting, very unfriendly and had no assessment benefit. In a research I did (whose report will be published soon) a medical teacher objected to using Facebook for class work, because she doesn't like being a Facebook friend to her students as there are some of her data she won't want the students to know. Truly, there are objectionable things students and other social media users can do to a teacher or a student on social media.

Again, most social media are open technologies that lack institutional support. This means that when a student is stuck using the chosen medium, help may be unavailable, and a teacher can run into a serious trouble if there's a matter arising against a student or the institution from use of such technology. Worse still, a medium may be here today and gone tomorrow, and all the valuable academic data you keep in it may be lost before you knew it. Check www.wikispaces.com that was a very useful tool to many higher education teachers when it was alive.

In spite of the mentioned and other barriers, Facebook, YouTube, Twitter, Instagram, WhatsApp, Telegram and several other social media can be adapted to be a beneficial informal learning management system (LMS) especially in contexts where a college adopts no standard LMS. A class can be a closed group on these sites. This and some ground rules will ward off intruders and unwanted communication and other unwholesome behaviour, and, as in a LMS, reading materials, assignments and discussions can be held on the sites. These have the advantages of, among others,

1) making a student's material or idea readily accessible to other students,

2) encouraging useful peer teaching and assessment,

3) encouraging more student participation in class activities, as shy students "speak" boldly in this situation without fear of faces or of being ridiculed.

My research project I mentioned above found all these and more benefits.

With the ubiquity of mobile phone and some telecom companies’ lowering cost of accessing some social media through them, social media can prove to provide the only e-learning experience most students and teachers may have in resource-poor areas and in contexts where technology is being newly embraced. This can only be when teachers strategize properly—setting learning goals—and teachers and students are well acquainted with the social medium they adopt. They can avoid or minimize a whole lot of privacy issues through the Settings feature of the platform.

This paper has more relevant insights: http://ijedict.dec.uwi.edu/include/getdoc.php?id=6319&article=1868&mode=pdf. Also I'm designing a course to help teachers in higher education use social media effectively for optimum teaching and learning outcomes and will give update here when ready with it.

Barriers I have identified in using social media:

a. Unstable security and privacy concerns

b. Technology is not user friendly/difficult to use

c. Internet connection costs too much

d. Internet connection is unreliable

e. Unstable electricity connection

f. Too Busy/Don’t have time

g. Lack of support at my institution

h. Integrity of student submissions

Benefits:

1. Source of information

2. Provides a platform for sharing knowledge

3. Easy collaboration on projects.

4. Makes team work easier and many more.....

More student engagement as it's almost their second language, but the risk of cyber bullying etc is their so that these sites must be monitored. Here are examples of how it has been used to increase student engagement and communication in teaching and learning:

Article Use of Facebook for enhancing student engagement in a higher...

Conference Paper Social Media in Education: Bringing Your Classroom to Life -...

Best,

Debra

Large parts of the previous answers refer to the barriers of utilizing social media applications, and I agree with many of them. However, I think its also important to mention potential benefits: In my opinion, there are two main reasons why researchers and practitioners recommend the use of digital learning environments in higher education. First, in an increasingly digitalized world, education needs to be digital as well (Wilson, Scalise, & Gochyyev, 2018). Students should be encouraged and empowered to use social media for communication and collaboration as well as for learning and knowledge exchange in an appropriate way, to become competent and proficient members of a knowledge society. Second, social media promise to make learning and teaching more effective, for example, by increasing learners’ motivation, adapting to students’ prior knowledge, or providing the possibility for mobile and ubiquitous learning.

Wilson, M., Scalise, K., & Gochyyev, P. (2018). Learning in digital networks as a modern approach to ICT literacy. In E. Care, P. Griffin, & M. Wilson (Eds.), Assessment and teaching of 21st century skills (pp. 181–210). Washington, DC: Springer.

Joachim Kimmerle thanks for using correct quotes. Though this is an academic platform some people not seem to know that a link is does not fullfill the criteria of a scientific quote.

Amal Alaradah uploading material in a LMS is THE problem most people have with "E-Learning" because THAT is not E-Learning. MAking student trust each other or each others content. Making students get the feeling of working on a "big thing". To Overcome the the "i-will-survive" attitude of students (I dont have to participate in collaborative/Cooperative learning szenarios because I will pass without the knowledge/competencies of my fellow student) will be one of the most challenging tasks for teaching academic. Students have to get the "give-and-take" feeling to get into a more cooperative habitus of learning.

Ebner, M., Kickmeier-Rust, M. & Holzinger, A. (2008). Utilizing Wiki-Systems in higher education classes: a chance for universal access? Universal Access in the Information Society, 7 (4), 199–207. https://doi.org/10.1007/s10209-008-0115-2