I was in the Deciat system, going to Farseer and was interdicted and killed by a real player, is this allowed? is it a in-humble thing to do?
As you have learned by now, it is allowed, and some players thinks this is good gameplay, lets just accept some people have strange ideas on what is good gameplay, and move on.
Most of these courageous players doing this, utilizes another feature of Elite, namely the mode switching, so just to generalise this a bit, the above players, only play in open, when they are in their best ships for killing other players, when they need to do some engineering in a "new" ship etc, they simply do nto do this in open, they choose to do this in Private Group or Solo, so they do not risk being another players amusement....
So you have quite a few options here.
* Rise to the challenge, learn how to avoid getting interdicted, as these players are most likely better at this than what you are.
* When doing this sort of things, like visiting Engineers, and other popular places, like Community Goals, do this in Private Group/Solo. This is equally accepted as the random killing of players that you suffered.
* Give up and play something else, do not forget to create I leave this game, so that other players can request to have your stuff.
* Get even, team up with other players, learn the tactics, build your own killer ship, and go hunting for these murderers.... should be easy to spot, these are the wanted players.... and if are better than they, you will learn a new tactic, that is not allowed todo, and that is what is called Combat Log, where certain players that is facing defeat uses a sneaky way to avoid death, in short, your computer/console encounters a catastrophic failure of some sort.... it can be that the network cable got unplugged, or the process that is Elite Dangerous mysteriously crashed/got killed, or the entire unit simply crashed, like the power plug jumped out of the socket....
And then there are all sorts of variants of the above.
So I hope this was useful and somewhat amusing, as this kind of threads often soon degenerate into a stalement, where both sides go to extreme end of the this and refuse to change, and the worst thing you can do is to try and resolve this by using logic and suggest changes could actually work...