Can anything be done about these people?

Sometimes yes, sometimes no. The griefers with the oversized, two-seater, Central Park Paddleboat speeders often know exactly where to position their manhood compensator so the vendor or mailbox or whatever is completely hidden. But if you don't mind swallowing the aggravation and wasting your time, you can, of course, choose to roll your mouse around the screen, hoping to luck into the icon, or run from side to side, or jump up on the counter, or...

Why should you? Why should someone who simply wants to interact with a terminal or NPC in order to check their mail or buy a needed item have to dance around some giggling adolescent whose sole purpose is to interfere with other players?

Ban speeders on the Fleet. As someone said, it takes 60 seconds tops to run the circumference of the space station, and if the speed is so important to these people, why are they spending sixty minutes parked on top of a mailbox.

If there is somebody on your way on the vendor you can just switch instances to second one or third one and hope that there isn't a another guy doing that. Offtopic but you can switch instances in black hole also if the first one has too many people in it.

Nothing short of an area around vendors would really work i'm afraid. I have seen this in every MMO since Everquest to some degree whether it be a large mount(remember the elephents in lich), flapping wings or just large body(ogre's and trolls in vanilla EQ). *oops combined analogies* One of the worst I ever saw was someone set in rift, They created a guild named 'dye vendor' and stood perfectly still for hours laughing every time someone clicked on them.

A dismount when you click on the GTN would help, and would be nice. Won't help with the people that just sit there doing nothing, though.

It may be harsh.. But perhaps taking the mount away from someone after they recieve like 10 complaints from 10 different accounts or something.. 10 complaints for blocking stuff with their mount and they lose the mount off of all their characters.. That will get around pretty quick and people will stop blocking stuff..

Sadly, Bioware retired an entire family of mounts because of this issue..

Perhaps a better approach would be just to make the areas around mailboxes, GTN Kiosk, all other vendors, and any other place that requires a player to interact by clicking, simply a no fly zone..

I am not sure I like the idea of making the entire fleet a no fly zone.. But I would support it as I feel it is the easiest solution..

I just move the camera and click on the NPC's feet or the base of the terminal... speeders hover above the ground so they can't block it

How about if they just blow up and lose a level.

Things like that tend to enhance the thoughtfulness of thoughtless people. ;p

Nope. I still say blow them to hell and make em lose a level, maybe all their gear, maybe blow up their computer.

Ok, a little less harsh would be to not ban all mounts on fleet, but ban anything beyond a bike type.

Easy to solve, Remove vehicles from the fleet or in doors for that matter.
i know ppl will cry about it but its better to take those extra 10 sec to get somewhere then to standstill trying to turn in stuff for 20-40 minutes.

Possible Solution:

1. Move the terminal from the "corridor" area and place it more in a cubby hole similar to the vendors.
2. Do not allow mounts in those cubby hole areas.
3. Have a small invisible wall around the NPC/Terminals so that players cannot all stand on top of the NPC.

OR Have a hotkey to interact with nearest NPC/Terminal.