More the opposite. Your contract says 8 hours, but everyone does 11 on average, so there is no way you could dispute ownership of those results.
Secondly most IT companies have 'innovation participation' programs that want to have first dibs on all your creative ideas, whether it's on the clock or off.
Thirdly, in an industry with very low start-up costs (all you need is a computer)and high competition for talent, even the potential threat of a former employer claiming IP over your new business can be a potential deterrent that nudges people into just not do it.
Secondly most IT companies have 'innovation participation' programs that want to have first dibs on all your creative ideas, whether it's on the clock or off.
Thirdly, in an industry with very low start-up costs (all you need is a computer)and high competition for talent, even the potential threat of a former employer claiming IP over your new business can be a potential deterrent that nudges people into just not do it.