Ask HN: VOIP service encryption

It appears that most commercial VOIP service providers do not use encrypted SIP or RTP nor do they seem concerned about the lack of encryption.

The common response seems to be that it would add jitter, cpu overhead, and still be unencrypted on the PSTN. All valid points but it seems any security and privacy is better than none at all.

VoIP.ms, for example, even goes so far as to suggest the SIP packet is secure simply because it uses an MD5 password hash[1].

How do other VOIP service users feel about this issue?

[1]: http://wiki.voip.ms/article/FAQ#Does_VoIP.ms_encrypt_the_communication_.3F