Blind hatred or just blind?
@ .3
If you had read his comment, it sounds like he's actually taken the time to investigate the contents of this file from his iPhone and has not found per second data, has noted accuracy "only down to about cell tower level" (i'm guessing he's not in the position to go and work out exactly how accurate), and has not seen his home location more than once in the data (and I'd guess he's being going there most days in the past 6 months). Kind of at odds with the article, I know, but why shout at /downvote him instead of questioning the article?
Also, it may be that it *is* a cache file, it all depends on how many duplicate entries one can find - if you find lots then it's more akin to a log file (which should be purged regularly), if you find one then it's most likely a cache file (which really should be limited in size and have least used records removed on a regular basis).
@ PerfectBlue
Your assumptions seem to indicate that encrypting backups is not that much of an issue.
1) Most people won't think about encrypting a back-up (a checkbox on the device's "home" page - not exactly hard - but let's run with the assumption)
2) Only Tech savvy people will encrypt.
3) Hardly anyone backs up their devices anyway.
Based on the above, it seems like the issue of encrypting backups won't affect most people and the chances are pretty good that those who *do* back up are the tech savvy ones (we like backups, after all) who will encrypt said backups.