I think I'd be tempted to make this smaller - it's a bit hard to parse with the nested `if`s and the `else`. Suggest:

```ruby
      def raw_paths
        return [] unless (paths = params[:paths])

        # Efficiently match any combination of new line characters:
        #     http://stackoverflow.com/questions/10805125
        paths = paths.split(/\r?\n|\r/) if paths.is_a?(String)
        paths.reject(&:blank?).map(&:strip)
      end
```