No, but if you see someone digging around in that bin, especially someone who isn't seated in your row, you can be alert to the situation. There's never anything in my carry-on that's worth stealing, or that I can't live without, so I never worry about it. But, if yours is stuffed with expensive jewels, you may feel safer having in under the seat or, as mentioned by a previous poster, in the bin across the aisle.