I assume the question regards any sort of blotting stamp for security purposes. Folks seem to like these as an alternative to paper shredders as they are smaller, quieter and portable for obscuring personal information on printed material. While shredding makes sense for a lot of papers, sometimes you just want to throw those credit card offers in the trash and the only incriminating information is your address. A quick stamp, stamp, stamp might be enough to make it possible to throw the papers in the recycle bin.
The general term to describe these stamps is ID protection stamps or ID Guard stamps. I definitely think that the Max Korkoro model, with the rolling stamp and ability to refill the ink easily makes a good option. The price for any ID protection stamp seems to be about $10 which seems reasonable.
The only thing I don’t know looking at the photos and description is whether the ink is water resistant when dry. That would be the winning feature. If its water-soluble, then someone might be able to wash the ink off reveal your address or account numbers.
So I suppose I ought to order one and put it to the test, huh?