Also probably should point out that, that seems.you can only make a volte call from one volte enabled handset to another on the same carrier. Luckily Verizon is slow to enable, if you use the video calling list as surrogates for volte ready i have all of 9 out of hundreds of contacts that are ready on vzw. (Everyone would be different of course)
The author of this article clearly did not read the ACM paper he links to! The author makes it seem like, if you have an android phone, your phone is now wide open to someone installing apps on it and exploiting it without your knowledge. Almost all of the exploits that ACM paper details relate to exploiting the network, not the phone itself! The only phone-related exploits they mention are ONLY IF you install an app that has bad stuff in it (leading to, at worse, blocking phone calls, call spoofing, or over-billing). The article failed to mention who is most at risk -- Verizon and AT&T!!! What are they at risk for? Users getting free bandwidth using VoLTE channels (because they bill VoLTE by the minute, not by data). Denial of Service. Cellular user establishing a free P2P (like a torrent) network via phones. Billing of unwitting users.
Also, this article makes akes it seem like it is the fact that the phones are Android phones that the security flaws exist. Nowhere in the ACM paper do they say that Apple phones are not vulnerable too! It's just that nobody has tried it yet because it is harder to do, probably.