As a fan of Science Fiction one reoccurring theme is technology going wrong, either from it becoming sentient or from a madman throwing a wrench into the works. This last year I really enjoyed watching a series called Sword Arts Online when I saw the premise I was like this reminds me a bit of the themes in .Hack\Sign even if the stories are entirely different. Mainly the fact that technology can go wrong. Both are about Virtual Reality games where things don't go the way people expected and their are victims.
It's been a long time since i watched .Hack but as i recall some kind of intelligence was born within the game causing the various anomalies to occur such as Tsukasa being trapped within the game. The people who were harmed was on a much smaller level in this virtual reality game then in Swords Arts Online. However, both series deal with complex issues such as escapism, and interpersonal relationships. Tsukasa plays the game in order to escape from the bad things in life and is a loner who is suffering. But in playing the game Tsukasa ends up unable to log out and thus the story unfolds.
In Swords Arts Online you have the games creator trap everyone within the game making it so that if you died in the game you really died. It's a game of survival. There seem to be themes running through the series about reality vs. virtual worlds and how people might show themselves differently online in a game verses what they really are. Someone might be more willing to commit atrocities in a game while in real like be a good law abiding citizen. In away you could say it addresses issues of people who are not comfortable interacting in real life and who find that it's easier to express themselves in a fantasy world. The main character Kirito even says that the world in the game seemed more real to him. We even find out later that the reason he became so immersed in gaming was to escape the fact that his parents are not his real parents. Like Tsukasa, Kirito is also a loner. He doesn't party up with others much and works hard. But the reason why Kirito is a loner is different from Tsukasa. Tsukasa has been hurt in the past but Kirito seems to not want to be a burden to others or to see anyone die. Kirito is the type who is heroic and cool as opposed to Tsukasa who is more leave me alone I don't care. Tsukasa is weak but Kirito is strong even if they are both lonely kids trapped in bad situations.
Stories like these reinforce the idea that you can't trust technology. You should always be wary of things. Also it also points out the fact that many find comfort in escaping into fantasy worlds who are lonely, socially awkward, or have bad stuff going on in there lives. Video games can be liberating but going to far can lead to trouble. MMO's can also give you the chance to be someone else they don't have to reflect your outer self. So yes I love video games. But one thing is for certain there's no way I'd play a game like SOA where you are left at the mercy of whoever. Once again Sci-fi asks that great what if question.