The same with passports - they don't need to hold on to your passports, because they can just block you from going out of the country using a centralised system. Also, they can block you from coming back to US by placing you on a no-fly list, without any explanation - making you take a very long and expensive ship journey.
Telephones - soviets would openly monitor your phone calls. US government does it from hiding, not telling you that you might be wiretapped. Again, different method = same result.
Letters and Parcels - only letters are protected, parcels can be opened at anytime by any postal office worker, if they have a "reasonable" reason to.
Censorship - not done openly in the US, but again - there is no need for it. They keep everything you write saved for future use, so even though you can write whatever you want on your blog, it can still be used to prosecute you. It effectively is censorship in my opinion, even if it's not censorship per se.
Registering where you're going, warnings that the phone call is being recorded, those things are about FEAR. It's deliberately letting you know that the government is in the driver's seat and you shouldn't even get started with counter-revolutionary thoughts. The information gathering is secondary.
Tiananmen square has probably more than 1 video camera per square foot. That's not to get better footage, it's to send message.
There might be a day when the US is the same, and this might even be a critical moment on the way to that day, but right now the fact that the US is trying to hide it's intel capabilities as opposed to rubbing them in your face makes them categorically different.
I see great similarity.
Velvet glove or iron fist, both are the controlling hand; but it is good to acknowledge that we are not completely in a locked down police state- yet. However, these are the exact canaries we should look for in our own society.
I do find the need to call and notify Fraud Detection in order to have resources while traveling a bit congruous to the Soviet style travel restrictions.
You seem to describe at least five stark differences:
1. If you wanted to travel out of your town - you had to register that fact with the nearest police department.
2. Wanted to travel abroad - had to apply for a passport, which was only issued for a strict number of days and had to be returned upon return.
3. If you were placing a phone call, it would always start with a warning "This call is being monitored. This call is being monitored".
4. The post office would open your parcels and letters.
5. There was book censorship on a massive scale.
Comparing the US today to drastic Soviet republics doesn't really help the conversation - these far-off hypothetical comparisons make it easier for other people to dismiss your argument.