There really isn't a connection between what we do when we announce we are hitting a base and spying.
We do it because we understand that we are a very large squad which does take a big force to up to defend against, it's more of a sportsmanship thing/we want a lot of red guys to shoot at.
Spying/Hacking is done a lot less then everyone thinks...just like other games, a lot of people think cheating happens a lot...it doesn't and when it does the person cheating is either terrible or looking to get a reaction out of people.
Honestly, I don't know why it even gets brought up...people are too paranoid, just fight and if you think something is up...send film to HTC, they do look at them all.