Scott K. writes: Having had bought several grading service encapsulated coins through the mail, this thought occurred to me: Have there ever been problems with tampering? (Opening up the capsules and placing lower grade coins in)? Yet another way for the crooks in the coin trade to rip off unsuspecting collectors?
Though there is great deal of controversy about coin grading, at least the holders are sonically sealed. That means that the holder becomes one piece of plastic. The grading services use this secure method of packaging graded coins as they are on the hook if the coin is obviously misgraded. Though I’ve opened many holders myself using a hammer and small anvil, the holder is rendered unusable. The grading services have a machine that opens the holders, it also renders the holder unusable and if the coin is reencapsulated it is placed in a new holder. I would think that your worries are unfounded.