Until you want that Explorer achievement, that is.
I was doing just that on Neve while I was waiting for a BG to pop, cruising through Darnassus (gotta love flying up the trunk of Teldrassil), and then I hit Azuremyst Isle. Typically, it's not a big deal. The guards throughout most of the Isle are the traditional level, so I got lulled to sleep thinking that all I had to do was pop into Ammen Vale and then scoot over to Bloodmist Isle to finish up the achieve.
Neve approached, forded the river, and rode her strider up the cleft and into the guards patrolling the entrance to the Vale. She got smacked at, but I didn't think anything of it until I turned her around to head back. She was immediately pulled off her mount and pummeled.
Did you know that the L90 guards hit for damage that range into the six figures?
And that using Invisibility to sneak past the guards won't work either?
I haven't had as much an exciting time getting that Explorer achievement since I got my original award on Quintalan on the Stormscale PvP server.
While I play battlegrounds, I typically don't engage in PvP play these days. That's a far cry from my time on Stormscale, where I made a habit of looking over my shoulder and I developed a healthy distaste for the Alliance gankers in Hillsbrad. Even then, I wasn't the sort to go out of my way to go after low level toons on the other side. (Now, if I caught an Alliance player going after some Hordies, that was another story.)
Being on a PvE server means that you don't notice the faction territory quite so much as when you're on a PvP server. That first time when I ventured into Loch Modan and I saw that big red "Loch Modan - Alliance Territory" flash overhead, I gulped. I was sure that tons of Alliance would just pour out from behind every boulder and I'd be a smudge on the ground. After all, when you get ganked in Tarren Mill 3-4 times a night, you learn to expect that stuff. Much to my surprise, however, I kept moving and nobody seemed to really care that I was in the area.
If I thought it was terrifying on a PvP server to cross into enemy territory, I was extremely underwhelmed when I did it on a PvE server. There isn't a big red "hey dummy!" alert, so you really don't get that sense of "things could go really really bad" that you get on a PvP server.
Unless you're a lowbie who encounters a max level toon from a rival faction, that is.
Her adventure with the Ammen Vale guards aside, Neve was cruising right along through Bloodmist Isle when she rode up toward the Vector Coil. There, toiling among Kael's traitorous Sunhawks, was a lone Draenei. I pulled Neve up to watch as he dispatched a nest of them, and then he turned and saw her.
If a toon could have a deer-in-the-headlights look, it was this guy.
Neve paused a moment longer, nodded and waved at the Draenei, and sped on her way. Happy hunting!