I hear this around a lot. So I thought I would offer a simple observation which leads to many ideas.
Censorship is running rampant on the internet. Ideas are being censored. Example: Bret Weinstein had proposed a new election structure, he formed a twitter account to spread the idea. It was then shut down by twitter. But its not just this, information everywhere is being controled. In comment sections, on social networks, websites are being shut down, links not allowed to be shared.
The internet was built as a technology to aggregate all that humans minds produce. Through censorship the internet fails to serve its purpose and becomes more a brainwashing machine.
Any activity which moves the internet closer to its intended goal will be successful. So if you are looking for ideas, think of Anti-censorship technology. Anything which can increase the flow of information on the internet.
What about setting up block chain based google
http://presearch.org/ Comes to mind.
Although I am looking forward to brave search.
Censorship is worse in other parts of the world, it's what gave birth to encrypted OTT instant messaging apps. There are ways around it but you have to play whack-a-mole like getting around chinese censors if you are a chinese citizen, or you have to use VPNs, foreign servers etc. It's a sad fact and a good area to build in but it has its ow problems like making some secret service that is then used by criminals etc.