It can be a difficult/complex time consuming process for Law Enforcement to identify someone hiding their identity via a VPN.
A lot depends on whether the VPN provider is cooperative or uncooperative with LE. The majority of VPN providers tend to be uncooperative in which case, there are several extra steps LE needs to take to force providers to cooperate. All this to say, unfortunately we could be waiting quite a bit of time for LE to track down the ransom note sender(s) aka cybercriminal(s).
My guess is the criminal(s) sending the ransom note emails to TMZ are using a VPN sending encrypted emails, otherwise LE probably would have already figured out who they are by now, maybe, maybe not, as it’s only been barely 3 weeks post disappearance.
At any rate, whether the ransom note sender(s) are connected to Nancy’s disappearance or just some opportunistic scammer(s) trying to cash in, LE/Feds want to identify and apprehend them asap for obvious reasons, so I trust the Feds digital forensics tech professionals are working on this behind the scenes, probably around the clock, we just aren’t hearing about it/how much progress has been made. Which is ok, they don’t owe the public those details and rarely disclose as to protect the integrity of the investigation.
At any rate, below are some links (there are 3 as imo each has info that I think is informative and pertinent
to the discussion) for more in depth explanation that hopefully helps answer some of your questions:
*Snipped from 1st link:
Can emails be traced by the police?
Law enforcement and government agencies typically have the right to request information from email service providers and internet service providers, including IP addresses, metadata and user data, which can help in tracing the origin of an email.
While laws and regulations may differ across countries, the majority of them require a search warrant, court order or subpoena for such information to be released.
The police might also be able to trace anonymous emails, but this largely depends on the sender’s methods to cover their tracks.
If they use a VPN and opt for a disposable email service that doesn’t require any personal information to create an account, it can be difficult for the authorities to track them down.
**Snipped from 2nd link:
What information can the police obtain from your VPN?
“The police can legally apply to obtain certain types of information from a VPN provider.” This includes:
- Logs of all the websites a user visited.
- Services used while connected to the VPN.
- Actual IP addresses.
- Connection logs (which provides details such as the time someone used a VPN to connect to a server).
- Billing information that shows your mailing address and banking details.
“That said, some VPN providers promote a
no-logs policy, i.e., they say their service does not store any logs in order to provide a further layer of anonymity. When the provider is forced to comply with a request for access from the police, there won’t be any data to pass on. But in most cases, there is some kind of data to be found. Billing information is typically available, which is why those wishing for secrecy prefer to pay in
cryptocurrency.”
“In addition, VPN providers vary in their level of cooperation.
Some are happy to provide information to the police when provided with the right paperwork. Others are largely uncooperative. But even for them, enough pressure can be brought to bear that they are forced to comply.”
***Snipped from 3rd link
What information can the police obtain from your VPN?
“Another way police may track VPN users is by obtaining
user activity logs from VPN providers. While many reputable providers claim not to keep logs of user activity, some do retain certain information such as connection timestamps or bandwidth usage.”
“Once they have access to these logs, they can analyze them for evidence of illegal activity or connections between specific users and criminal organizations.”
“Finally, police may attempt to infect a suspect's device with malware in order to monitor their online activity directly.”
Discover the ins and outs of email tracing, from spotting red flags to analyzing email headers, and take charge of your email privacy.
tresorit.com
VPNs are popular because they add security to fairly open Wi-Fi and public internet channels. But can VPNs be tracked by the police?
www.techrepublic.com
Learn how IP tracking can compromise your online privacy and security. Discover tips for protecting yourself from police and other authorities.
www.browserscan.net
IMHO