Set it at as high as 1000 points, if you fear robots. You may even take, for example, 200 points to people activating that privilege. Vision impaired people, like me, would be happy even at such a price.
The objective is allow for more participation from security-aware people, and also from vision impaired (me) and blind people. The question What are the pros and cons of supporting anonymous participation on Stack Exchange? even asks for anonymous answering, so my request seems to be more reasonable.