The advent of open access publishing, on SSRN or in an institutional repository like the Digital Commons, has led to a rise in spam from predatory publishers who solicit researchers to re-publish their articles for a fee. Jeffrey Beall, an academic librarian at the University of Colorado, maintains the Scholarly Open Access blog, and has done a great deal of analysis on this topic. He recently updated his list of predatory publishers and journals and includes a checklist of criteria for determining predatory open-access publishers. (Feb. 2017: Mr. Beall was forced to take down his blog due to threats of legal action by some of the publishers he included in his list.) There is an archived version of his website here.
LAP Lambert Academic specifically targets student authors, offering to publish their work in exchange for the copyright. LAP usually posts the work on Amazon and prints a copy on demand for anyone who orders it. Don't sign away your copyright
Many of these predatory open access journals are easy to find via Google. Authors and editors should find Mr. Beall’s list valuable as a way to evaluate these resources and avoid citing them.
In August 2016, the FTC announced it is filing a consumer fraud lawsuit against OMICS Group, a major predatory publisher of online science journals. An article about it is here, the FTC complaint is here, and the FTC motion for summary judgment is here.