As with any industry, most publishing companies are legitimate businesses, but some participate in unethical behaviours.
Signs that a publisher may be engaging in unethical behaviours include:
Publishers who operate in these ways do not provide any of the value added services offered by more legitimate publishers, such as a thorough review process and marketing. In more serious cases, unethical publishers may also strip authors of all rights to their research and solicit funds.
To avoid being caught out:
The publishing business is just that, a business. Publishers need to make a profit and have their own agendas. Each author needs to remain vigilant that their interests are protected.