Praise be to Allaah.
Since you have some doubts about the matter, and since you say that this kind of investment includes making it possible for users to access both useful and harmful information, and that more than half of users are accessing bad websites, then you should pay heed to the hadeeth of the Prophet (peace and blessings of Allaah be upon him): “Leave that which makes you doubt for that which does not make you doubt.” (Reported by al-Tirmidhi, 2442; he said that this is a saheeh hasan hadeeth). So forget about this field and look for another kind of investment which will be halaal. May Allaah help you and us to earn from good and pure sources.
Sheikh Muhammed Salih Al-Munajjid