Interesting! Have you considered reaching out to one of those (e.g. Citymapper) and see if they would like to work with you? Either employ you, subcontract you, use you as an API, or whatever! :)
I think it's really cool that you maintain such a service and maybe they can find in you a good partnership!
Another nit, the "abandoned" part is the one that was open sourced a loooong time ago. Since then, it underwent a ton of changes but yeah, it's within Facebook. So, not abandoned at all, but not available outside.
The main issue (as usual in big companies) is the large amount of inter-dependencies with internal systems. Scribe as-is today doesn't make much sense outside Facebook. And yeah, it could be cleaned up, mock the internal services and OSS it. But that's a lot of work, both doing it and maintaining it. And having all those mocks, etc "wouldn't be Scribe as-is either"in terms of how e.g. it scales and so on.
In any case, the storage (LogDevice, https://github.com/facebookarchive/LogDevice) which is a large part of the system was open sourced a while back and... sadly it went again into "not-maintained OSS".
Finally, you can get a similar-ish system working with OSS tools (e.g. fluentd + Kafka) that will also scale quite well and which IMHO can also made to scale to Facebook-size levels. So, the incentive is there, but there are OSS alternatives already available :)
It's really hard to believe that people still write stuff online without doing some basic searching. But here we are...
Here's a couple links to illustrate how RAMPANT knife crime is in the UK:
[1] For the year ending September 2019, there were 221 homicides involving a knife or sharp instrument recorded by the police. This figure is for England and Wales only and it excludes data from Greater Manchester Police (GMP).
[2] Recorded knife crime rose by 7% from just above 41,000 in the year to June 2018 to just above 44,000 in the year to June 2019, knifepoint rapes, robberies and assaults logged by police continued to rise.
I think it's pretty clear that your "rampant" is off BY A LOT. Knife crime in the UK is definitely not something to dismiss but guns (and gun crime and gun accidents) in the US tromp pretty much every other crime statistic in the "modern, civilized" world.
I think it's really cool that you maintain such a service and maybe they can find in you a good partnership!