I think its only illegal if you actually jam cellphones. Discussing theory or designing circuits probably not. I wonder if its illegal to jam cellphones in the privacy of your own home. Say, you have teenage kids... and you want to have some no cell times (homework, late night, daughter talking to her new scumbag boyfriend...).
Anyway, what was this thread origionally? Oh yeah, lazy college students...
There is no real way to filter those kinds of posts. I guess the moderator would have to decide if a post is a homework request. But how do you determine if they are requesting help getting started, or a completed assignment ready to to turn in? Basically, its always up to the readers to decide which topics to get involved with. Far as I know, this forum doesn't have storage or bandwidth problems, so its not hurting anybody but the lazy students...