BALTIMORE — The titles of the books tell a story–"The Spies Among Us" by Ira Winkler and "No-Tech Hacking" by Johnny Long.

Both Winkler, president of Internet Security Group in Baltimore, and Long, a security researcher at Computer Sciences Corp. in Falls Church., Va., make the point that while the topic of data security usually stirs thoughts of someone at a remote location breaking electronically into a computer to steal information, not every intrusion involves the latest technology.

For example, in an interview with InfoWorld, Winkler stressed how easy it can be for someone to tailgate by following an authorized employee into the building. Long noted in the same article that restrictions on smoking in most buildings have created huddles of employees gathered outside a back entrance for a smoking break. He indicated it's not that hard to blend into the group when they return to work.