Given that a local copy of the Selenium server and web drivers are required to run an automation test, i.e...
Is there any way to run a web service where, for example, when the user clicks a button a Selenium script will execute for them? For example, a bot that automates tweets, i.e. https://github.com/santafebound/twitter-story-teller, without actually referencing the Twitter oAuth API because the automation is done locally on the user's machine, i.e. opens a browsers, inputs auth information, and tweets using mouse clicks and keyboard events? This was just a concrete example, but the question applies equally to any other conceivable type of Selenium automation test.
Are there any inherent limitations to this method? Seems kind of dangerous to me so I'm thinking maybe browsers somehow block this kind of thing from functioning?