I had a similar idea but abandoned it for multiple reasons. 1) gdpr/avg. You can't record data in Europe about a landlord or an address without permission. 2)

I had a similar idea but abandoned it for multiple reasons. 1) gdpr/avg. You can't record data in Europe about a landlord or an address without permission. 2) landlords are not people that you want to annoy. Especially the bad ones.