It depends... like on Hijacked its ok since your team can easily come back. But in MW3 on the village map (I forget the name) with the cliff, that didn't seem fair to me. You had like a 5% chance of getting out of the spawn then.
But its not cheating. Its just using the system to your advantage. There are just times when it is over the top due to, for example, flawed map design.
I definitely would not call it honorable, though. But it is fair in most instances in my book.
Spawn camping is shooting people when they appear giving them no opportunity to fight back. BO1 Jungle and Havana Demolition had instances of this.
Spawn trapping is keeping the other team on their third of the map. It can be broken out of if the trapped team actually uses brainpower to try and escape (smoke grenades, overload one side of the map, etc)
Spawn trapping can and will sometimes be just spawn camping.
GT: Boomer and Tank Pretty darn confident..... I don't want to have to wait till the Microendony XBOXS 4ii comes out another 15 years later....
Be it spawn camping or spawn trapping, without it ie:MW3 style, it levels the game for both sides. Call of Duty is supposed to be about how well you use your weapons, perks, equipment, in order to accomplish the mission. Its not about "oh well if its iin the game then its fair game". A lot of people are cool with it so its whatever. For me it was harder to play MW3 than Blop2 and i liked that so now when I play i get bored when dominating and the other team doesn't even have a chance.
I'm 10th prestige and bored of Blop and BF3... Time to get a new game :P