Here is the DOI to the publication in case you are curious: 10.1016/j.measurement.2014.09.009. The "erratum" is kind of sad

Do you even job, bro?

It's common to receive a mail from some service that they're changing the terms and conditions of their service (internet provider, gmail, etc.) These changes are unilateral and can be about anything, from their privacy policy to the money they intend to charge me.

Why can't I unilaterally send them a mail and say, I am changing the terms of my patronage and will now insert my new policy (pay only xx amount, or demand a mint Chico chip ice cream every Tuesday)?

I will be entering the US in October to work for about a year and half as a visiting researcher. I will be accompanied by my partner and his two children.

I am very scared on what to expect at the border because of all the stories I hear about detentions, refusals, etc.

My concerns are:

1. Do they ask everyone to unlock their phones and download EVERYTHING in there for later analysis?
2. Related to point 1., refusing to unlock and give access will make you suspect and they refuse entry?
3. Do they also ask you to unlock your laptop? I have stuff encrypted there as I often have to process sensitive patient data for a project I am working.
4. Do they do a complete biometric data collection of you and the kids?

Also, how do we conduct ourselves at the border entry to avoid getting absolutely shafted?

P.S.: I am not in a position to call off the trip. Visa is ready and tickets are brought.

I'm fairly certain this post might end up revealing my lack of knowledge on this topic rather than being a sound technical question, but here goes:

Why are most people keen on VPN services when TOR was present all along? Is it just because TOR is "slower" than VPNs or some other reason related to access?

Here are the points that confuse me:

1. Many services block TOR.

True, but that's the case with VPNs too. Netflix, Spotify, or some government website (won't specify which country) will give you a tough time when they detect VPN use.

2. Your ISP will know you used TOR.

Sure, but they also know that you used a VPN. Not sure why so many people use this argument. Besides, if you use TOR bridges, your ISP won't know it.

3. VPNs are super helpful when trying to circumvent CG-NAT.

And you'd be right there. Accessing clearnet to serve or host a service is much easier with a VPN. But then again, most people aren't trying to circumvent their CG-NAT to host service. They're trying to use the web more generally.

This post was inspired by my utter disillusionment of Mullvad.

These creams have some chemical that blocks the UV with some capacity, say a factor of 50. Why can't I apply two layers of this cream to now get a 100 factor equivalent protection?

I asked the chemist at the store and they said it's not how it works and that the highest protection factor they have is 75 (which was super expensive).

What gives?

Edit: Thank you for those super informative answers.