Cheating becomes more prevalent and easier to do every year. With numerous sites online where one can purchase an "original" paper, the temptation for students is greater than ever to not do their own work. The "point and click, copy and paste" generation has not really learned the lesson that research is a slow process. People want instant gratification, and that means having a paper to turn in without doing any of the work. Many of the current generation of students are risk-takers, as well. They figure that they will take the chance of getting caught and deal with the consequences if they must. Many of them think that the teacher won't bother to read their work anyway. They are invariably surprised when they get busted. Many even go so far as to swear they don't know how that happened when the teacher has a copy of their word-for-word plagiarized essay attached to the original document.
Many of them are also surprised to discover that their teachers/professors are one step ahead of them. Every generation thinks it's reinveinting the wheel with tricks and ways to cheat. So, while it is easier to cheat, it is also easier to catch a cheater who uses the internet to buy or copy his/her work. All one has to do is type a phrase into Google (or the search engine of choice) and there it is. Plus, many schools now subscribe to Turn It In or other plagiarism detecting tools.
As far as ruining a student's future, well, he or she is doing that without the teacher's help, as most of the responders to this thread seem to agree. I make it very clear at the beginning of each semester what the consequences of plagiarism are. If the student still chooses to do so, he/she earned that zero.