Commercial location data, in this case acquired from hundreds of millions of phones via a company called Penlink, can be queried without a warrant, according to an internal ICE legal analysis shared with 404 Media.
https://www.404media.co/inside-ices-tool-to-monitor-phones-in-entire-neighborhoods/
This is true. In regards to Signal, they do always comply with the governments request for data. The things is, Signal has next to no data on you. So when they comply, they give them everything they have (which is next to nothing). You can see everything they have given up here: https://signal.org/bigbrother/