Facebook users are being duped into circulating a hoax message warning them not to accept friend requests from an account called Jayden K Smith.
The message, being sent via Facebook Messenger, warns that the account is a hacker who "has the system connected to your Facebook account".
Well-meaning users are sharing the message widely, but as with most viral Facebook posts, the message is a hoax. There is no evidence of any account with the name Jayden K Smith going on sprees of adding users, and even if there were, they would not be able to hack into an account just by becoming a friend.
Mass friend requests to unknown users is also against Facebook's terms and conditions regarding spam, so any such account would probably be quickly dealt with.