the blog post does not even mention warrants but the justia link does... I would be curious to know if a warrant is required for all people located in the area where such a device is used (which of course should be impossible).

A 3 sentence Google Plus post can hardly be called a summary of the opinion.

Well if we are frank the post didn't really had an opinion (a constructed argument) or a valuable summary of the actual case. If this type of content would be posted by a "complete no-body" (as is not some one of note either in the HN community or in any other community) it would quite likely have gotten flagged for being used to generate views when one could link to the content directly. Also quite a few people stay away from Google services like Google+ or at least prefer not to use them, so for those people offering the link to the actual court ruling might be of service.