Things you can do anonymously
I (obviously) prefer to keep my internet presence a mystery. What things can you still do to make money (not that I'm going to) while being anonymous?
1. Write books
People have been writing under pseudonyms for centuries. Maybe longer. There's a very low chance of this happening.
I've seen a lot of people gain a following (I don't want one) being anonymous.
3. Raise $ and donate
I think I'd be ok trying to raise money for a good cause (taking a percentage like any non-profit) and then donating that money anonymously. But, the big donors usually like to be given some credit. So, not sure this is viable.
4. Help political candidates
Similar to #3. I don't want to be a candidate, but would be fine with trying to help some in the background.
I suppose you can do this, but not aware of any.