By that logic, attractive women who go out in public wearing skimpy outfits are committing theft - but I would not want to make dressing sexily and then going out in public illegal. I think there is something about the airplane banner at the beach and the slick hyper-calculated megacorp advertisement that pops up on the website you visit that is annoying for reasons other than theft - it is not so much the grabbing of one's attention that is annoying, but rather what grabs it and what the intentions behind it are and what context it happens in. Part of what makes many ads suck, I imagine, is that people deliberately design them to be unpleasant - which is why so many of them are garish. They stand out in part because they actually are meant to be annoying. In which case it is not so much the grabbing of attention that is the problem as what grabs it and what the intention is - in the case of the deliberately garish ad, your attention is grabbed in a deliberately unpleasant manner by a team of total strangers who work for YetAnotherSlickModernCorporation, want only profit, and are probably not offering you anything that you want.