Yes, do be careful - especially if you're not well versed in the use of a hand held grinder with a cut-off wheel. I watched a guy snag a cut-off wheel while cutting some ¼" steel angle and the grinder almost jumped out of his hands. I told him to put on a pair of gloves and he shrugged it off. It grabbed again and this time went right across the back of his hand. He got some stitches to remind him to wear gloves that time. He's lucky it wasn't worse yet.