Random Manager posts about uncovering disturbing background about a company when researching before pursuing an opportunity:
It may not bother some candidates that a company’s executives are members of a cult that is popular with certain Hollywood celebrities. However, when there is evidence that principles from the cult are being used as management tools within the company, that’s a clear sign to run, not walk, from that opportunity.
While finding out that the company may be run by Operating Thetans makes for a good horror story, the reality doesn't have to be that creepy to make the research worth your while. When you go researching your potential future employer, I suggest looking for people who are part of the company, and find what they have to say.
Maybe you'll find a former sysadmin who blogs openly about how things go at the company. What if the IT department is in the middle of political upheaval over whether to move to Oracle or stick with PostgreSQL? Perhaps the company has had trouble hiring developers, and you'll want to ask about that at the interview.
No matter what you find, or don't, the potential goldmine of information available about your prospective employer makes some online research well worth the investment of time.