I was talking with Brenda recently (we do that a lot) and she gave me something new to worry about.
Whenever a student of mine gets a job in the industry, it reflects on me, personally (because most of the time, I'm the only person from industry they've had direct contact with in a classroom). In other words, my students may affect my ability to get industry contract work at some point.
The assumption is that if I taught them everything they know, then their skills and abilities are a reflection of my own. This isn't entirely true, of course, but it doesn't matter. A lot of people believe it's true, therefore it influences their perception, and perception is everything when it comes to reputation. I say "my" here, but this really applies to any industry-based teacher, especially at a school where they're the only one of their kind.
Sometimes this works in my favor. Last year I had two absolutely brilliant students who made it into the industry, and they're making me look good, through no fault of my own.
Sometimes this works against me. Maybe some day I'll have an absolutely horrible student, who somehow blunders into an industry job and screws things up horribly. If I'm asked to provide a recommendation I can be reserved about it, but beyond that, I have no defense against this. But it's still a potential black mark on my record.
I suppose if one is really paranoid, the best defense is to work for a university that has overly selective admission requirements, and get oneself installed on the admissions board. For the rest of us... I suppose we just have to cross our fingers and hope that we get more good than bad (and that maybe we can be enough of an influence on enough of our students to make the difference).