Blockchain

Blockchain is essentially a group maintained database. It is most frequently applied to cryptocurriencies because it allows the whole community to either validate or invalidate transaction histories. This is useful because if someone attempts to create a false transaction history that goes into the next block then it can be rejected because the majority of other people will detect that it is incorrect. By design it is very difficult to falsify and were it to be successfully and consistently broken then it would become worthless as it's value lies in people agreeing to hold value in it and if it becomes untrustworthy they would immediately stop using it in favor of another cryptocurriency.

Basically how it works is by hashing. Each "block" is a hash of hashed transactions plus the hash of the last block but in order to finish a block you have to solve a puzzle that can only be worked out by brute force. The puzzle is usually a leading 0 problem where they give you some number and they want you to add something to it and the result must hash to something with some leading number of 0's. The number of 0's required is scaled so that it will on average take some rough amount of time so that blocks actually have some content before they are added to the chain. Once someone solves the puzzle everyone can easily verify that it's correct and then they move onto trying to solve the next block.

A lot of companies are trying to use blockchain in places that really aren't suited for it but because it's a huge up and coming technology everyone wants to say that they're using it. It's use case is fairly limited in that it only really works well for problems where you require group consensus before changing something in the database. The benefit of using a blockchain in this situation is that you can be sure that it is very secure. The drawbacks would be things like you have to have a network of people using it and constantly working on solving blocks which can require high power gpu's working almost always which will add up in electricity costs.

Discord Privacy Policy

I think that the things that surprised me most in this privacy policy were in fact good things such as when Discord collects data it's kept within Discord itself and its affiliates and they use the data to somehow better their service or track how much it's being used. They also allow the developers to have access to message content and metadata as well as audio metadata in order to further improve their text and voice services. I can't actually think of anything in their privacy policy that I seemed inappropriate or wish was different. I think they do a good job of keeping sensitive data protected and even not so sensitive data is kept within companies related to their service so they aren't selling my information to anyone. I did not know the details of the privacy policy before I started using it and I don't think it affects my usage of the software at all. Discord is so useful to me that they would have to be doing something like logging all messages and voice content of every user with their real identity on a public website that anyone could easily find you and listen to every call you've ever been in and read every message you've ever sent in order for me to not continue using it.