Body positions on the client happening for other players?

Help and Feedback Scripting Support
1

So I made a similar dragging system from the one in lumber tycoon 2.

I used some code from Heath Hasikins Video.

I showed my friend and for some reason he can see it when I drag an object.

This is the code(Code is very messy I still need to clean it up.):

local Player = game.Players.LocalPlayer
local Mouse = Player:GetMouse()

local DragBall = nil
local Grabbing = false

function addBodyPos(part)
	local BodyPos = Instance.new("BodyPosition", part)
	BodyPos.MaxForce = Vector3.new(1000000,1000000,100000)
	BodyPos.D = 1000
	BodyPos.P = 10000
	
	local BodyGyro = Instance.new("BodyGyro", part)
	return BodyPos
end


function weldBetween(a, b)
	local Weld = Instance.new("ManualWeld", a)
	Weld.C0 = a.CFrame:inverse() * b.CFrame
	
	Weld.Part0 = a
	Weld.Part1 = b
	
	return Weld
end

function creatBall()
	local ball = Instance.new("Part", workspace)
	ball.Shape = "Ball"
	ball.Name = "DragBall"
	ball.BrickColor = BrickColor.new("Really blue")
	ball.Material = Enum.Material.Neon
	ball.Size = Vector3.new(0.5,0.5,0.5)
	
	return ball
end

Mouse.Button1Down:Connect(function()
	Grabbing = true
	local Target = Mouse.Target
	if Target then
		local NewDragBall = creatBall()
		NewDragBall.CFrame = Mouse.hit
		DragBall = NewDragBall
		
		local DragBallWeld = weldBetween(NewDragBall, Target)
		local BodyPos = addBodyPos(DragBall)
		
		while Grabbing == true do
			local cf = CFrame.new(Player.Character.Head.Position, Mouse.hit.p)
			BodyPos.Position = (cf + cf.LookVector * 10).Position
			NewDragBall.BodyGyro.CFrame = CFrame.new(Player.Character.Head.Position, Target.Position)
			wait()
		end
	end
end)

Mouse.Button1Up:Connect(function()
	Grabbing = false
	if DragBall then
		DragBall:Destroy()
	end
end)

I want to know why this happens.