If it can be made configurable.

Most of websites use HTTPS exclusively which has effectively blocked every single one of Symbian (except of OperaMini) and Blackberry. Last 2 years HN has joined to this.

I don't personally have a need for such a thing, but having worked on 'bot blocking' solutions, I think it would be popular.

There is a lot of talk about "browser agents" vs "recursive crawlers", but that discussion misses what site owners want.

Products that use "browser agents" often dis-intermediate the sites they scrape even if they link back. While users may prefer those user experiences, content owners will pay to block that to retain control over their presentation and monetization friction.

Many news sites already have these sorts of captchas, proof of work, behavioral analysis roadblocks. Players like Cloudflare and Tollbit both offer bot blocking proxies as well. This tech is here and service owners want it.