Most mobile wallets allow you to paste in an address to send and add a receiving address to your clipboard so you can send it to someone the access itself is not that big a deal. With that I just played with a few wallets on my phone and most of them just took things from the clipboard without asking. So it appears to just be 'the way it's done'
On mobile at least, copying and pasting addresses seems to be the only way to send coins to it if it is located on the same device (if not, well QR codes solve that issue nicely, but then the below still applies).
But on desktop, I always verify that the address I copy is the same as the address listed on the screen. All characters are checked. This at least gives me peace of mind that there is no clipboard malware running amok.
