```ruby
class UsersController < ApplicationController

  before_filter :logged_in_user, only: [:edit, :update, :show, :index, :destroy]
  before_filter :correct_user, only: [:edit, :update]
  before_filter :admin_user, only: :destroy

  def index
    @users = User.all
  end

  def show
    @user = User.find(params[:id])
  end

  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)
    if verify_recaptcha(model: @user) && @user.save
      log_in @user
      flash[:success] = "Welcome to Ecotone!"
      redirect_to @user
    else
      render 'new'
    end
  end

  def edit
  end

  def update
    if @user.update_attributes(user_params)
      flash[:success] = "Account updated"
      redirect_to @user
    else
      render 'edit'
    end
  end

  def destroy
    User.find(params[:id]).destroy
    flash[:success] = "User deleted"
    redirect_to users_url
  end

  private

  def user_params
    params.require(:user).permit(:name, :email, :password, :password_confirmation)
  end

  def logged_in_user
    unless logged_in?
      flash[:danger] = "Please login"
      redirect_to login_url
    end
  end

  def correct_user
    @user = User.find(params[:id])
    redirect_to(root_url) unless current_user?(@user)
  end

  def admin_user
    redirect_to(root_url) unless current_user.admin?
  end

end
```

Simplify conditions of logged_in_user filter.
user
```ruby
class UsersController < ApplicationController

  before_filter :logged_in_user, except: [:new, :create]
  before_filter :correct_user, only: [:edit, :update]
  before_filter :admin_user, only: :destroy

  def index
    @users = User.all
  end

  def show
    @user = User.find(params[:id])
  end

  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)
    if verify_recaptcha(model: @user) && @user.save
      log_in @user
      flash[:success] = "Welcome to Ecotone!"
      redirect_to @user
    else
      render 'new'
    end
  end

  def edit
  end

  def update
    if @user.update_attributes(user_params)
      flash[:success] = "Account updated"
      redirect_to @user
    else
      render 'edit'
    end
  end

  def destroy
    User.find(params[:id]).destroy
    flash[:success] = "User deleted"
    redirect_to users_url
  end

  private

  def user_params
    params.require(:user).permit(:name, :email, :password, :password_confirmation)
  end

  def logged_in_user
    unless logged_in?
      flash[:danger] = "Please login"
      redirect_to login_url
    end
  end

  def correct_user
    @user = User.find(params[:id])
    redirect_to(root_url) unless current_user?(@user)
  end

  def admin_user
    redirect_to(root_url) unless current_user.admin?
  end

end
```
assistant