I really don't understand the point of removing IC markings. The kind of people who do this, are usually people who
- Don't have a clue about how good a determined person or group can be in figuring out what parts are used. Blank IC's won't change (and hardly delay) the outcome of a serious reverse-engineering attempt.
- For a mass-produced, commodity item no-one will care. Competition is already making the same & don't need your help anyway.
- Or you've taken somebody else's design without permission (possibly illegal depending on where you are & where products are sold), and don't want the rest of the world to find out.
The only result is making it hard for people to repair your product, when that is needed. For me personally: if manufacturer scrapes IC labels off, I would take that as a clear indicator that manufacturer is 'ashamed' of its work or has done something shady, and steer clear of that product.