Beginning December 13, 2017, FamilySearch.org will begin requiring all visitors to sign in with a free account in order to search records. They say the reason is because some of their partners require their source documentation to be accessed in a safe and secure environment. Look at it this way, if you were a church or other organization that had the personal details of their members, do you want anyone at all on the Internet to access this information? While it's true that even scammers can create accounts on FamilySearch, it is unlikely they would actually go through this trouble to do so. In addition, FamilySearch wants to create a more personalized experience for you. In order to do this, it needs to know who you are when you are on their site.
I've been signing on to FamilySearch most times I've done research on their site for well over 10 years. It's never been a problem and the worst they'll email you is updates on what new records they've recently acquired and occasional helpful hints.
I encourage everyone to create an account on FamilySearch.org. It's easy, free and will soon be required in order to perform research on their site. By doing this, I believe it will allow them to acquire more documents they wouldn't have been allowed to have if they didn't begin this requirement. Go ahead and get your account created now so you'll be used to using it by the time it is required. I promise. It won't hurt.