swords are very much like computers in a lot of ways. The first one being that both can be used to harm people. A computer can send out viruses and be used as tools to hack other computers, they can also be placed in murder weapons like guns and missiles to make them fire and kill by themselves. a sword can be used to hurt or even kill people.
the second way is they can help people. a computer can be used to contact long lost friends and to help with some complicated tasks, some can even save lives like the one computer that calculated its way around the moon to use its gravity to save the astronauts lives when they ran out of fuel on a lunar mission. a sword can be used to protect the helpless and the oppressed just like kenshin and some other characters in the anime rurouni kenshin.
and lastly the third way. one can use a powerful expensive gaming computer as bragging rights just as a sword can be used as bragging rights when talking to a friend or rival.
one way that it is different. formal sword training teaches ethics and good conduct but computers don't necessarily do that.
the second way they are different is that swordsmanship gives the swordsman good exercise for the mind and body but computers all they exercise is your thumbs and wrists.
so if it's not illegal to carry around computers why cant we carry around swords if they are so similar. the answer is simple, the government sucks.