What are the disadvantages of jailbreaking an iPod/iPhone?
 

I plan on getting an iPod 4G soon and there are some tempting applications from Cydia which requires jailbreaking.
It's not illegal, except that Apple refuses to grant you your warranty if you turn in a jailbroken spoiled iPod/iPhone
So, I just want to know, other than the disadvantages of not having a warranty, are there any other disadvantages to jailbreaking?

ios jailbreak