One of the biggest problem in the social networks (SN) today is that these network are has not any resiliance against atacks against freedom or control. If a goverment wants to remove the free spech, they can just block the access to the central servers of the SN (usually they block only DNS which is impressively incompetent, but they can improve this control mechanisms in the future). To avoid this kind of control we need a distributed SN, which multiple nodes in different physical locations. As far as I see, a truly free SN must have the following features:
When handling a lot of access log records (actually this approach should work for any other kind of structured log), usually you spend a lot of disk space saving the logs. But, if you analize the content of that logs you probably realized that there are common patterns there. In fact, you have a limited number of available paths for your server requests.
During a conversation with my colleages about the complexity of an algorithm which requires to iterate a long list of elements, we talk about the posibility of that algorithm was squared time complexity due to the way tht it was implemented, but we stop a while thinking if any iteration over all elements of any set (or sorted set) could be less than O(n).
One of the major problems with python applications is that they required to install the entire python virtual machine and core library to run. This is not a problem in most cases, but sometimes could be annoying, specially in machines with few resources.
One of the major problems related with some backups, for example GnuPG keys backup, is that the most secure way to perform this backup is traditional paper. The old fashion hard copy is most durable backup system ever invented and, also, is easy to keep safe and recopy.
With the rise of cloud computing there are also new paradigms in order to provision hosts as fast as possible. In this scenario some utilities like Puppet or Chef are the most popular ones. But though the utility of that applications is well known, they only cover the OS point of view provission, but forget completely the infrastructure behind that.
Few years ago I was working in design of a large cluster of systems to perform some actions (solving some mathematical models, sharding database). From the point of view of the systems, I had to deal with a number of pesky troubles. One of them was the user management.
A couple of years ago I was talking with my colleages in those years about security in some websites. We were not talking about SSL (which is, by the way more popuplar now), because SSL only works at connection level. With SSL you can guarantee that the communication is reliable (in terms of authenticity) and that the endpoint server is actually who pretend to be.
The connections in the WWW trend to be more secure each year. Probably for the 2020, all connections in WWW becomes across SSL protocol. That's a very good news for security, but although the idea to secure any HTTP connections is great, bring with it another problems that some people avoid to confront.