IT Employees Overworked?

Are IT Firms out there taking advantage of their employees? My sister just joined a small software house consisting of 6 employees who happens to provide solutions to a multi national company in Cyberjaya. The employer of this company expects the staff to work daily from 12 to 14 hours including weekends. The staffs are informed last minute to work on weekends for 12 to 14 hours without any compensation. What is wrong with the employers? Weekends are for resting and fully charging up for the following weeks. Why are they required to work long hours daily? Why are they required to work over the weekends when they are suppose to be resting? This is worse than a factory worker. The employer has definitely gone over board. Is this due to poor project management? How can a human be treated like this? Can something be done? This is not the first IT company doing such a thing.
To employers out there, please treat people the way you want to be treated. Be considerate and treat your employees better as they are your greatest asset.