Hi, I'm developing a follow feature for a customer and i realize that is not possible to fetch activities from many authors.

So i sugest this change:

        @scope.each do |event_type|
          constantized_providers(event_type).each do |provider|
            e += provider.find_events(event_type, @user, from, to, @options)
          end
        end

to

if @options[:author].is_a? Array
  @options[:author].each do |a|
        @scope.each do |event_type|
          constantized_providers(event_type).each do |provider|
            e += provider.find_events(event_type, @user, from, to, @options.merge(author: a))
          end
        end
  end
end

Sry for don't submit a patch, I'm not on my pc now and I don't have svn instaled.