Can I use a facebook, twitter and youtube logos at the back of my book cover?

[rohit]

Will it be a copyrighted issue or not

[Ricki]

Yes, if those logos are copyrighted in your country OR where you plan to sell your book using them is a copyright issue. Best not to do it.

[Steven J Pemberton]

It'll probably be a trademark issue, not a copyright issue. You probably won't be allowed to do it unless you have permission from those companies, which you're not likely to get. You may be able to get away without asking permission if you use the logos in a way that doesn't imply your book is in approved by those companies, or in any way an official product of theirs, but this is harder than it looks.

[Piratemom]

If you are using them as in Follow me on Facebook and Twitter and see my video on YouTube, then no problem. But if you're trying to weave them into your story, or for any other reason than to say "Look! Social media!" then you might be in trouble.