One of the deficiencies of the Internet is thatthere is no editor to deal with false or defamatory content.  However,assuming that the consumer's "bashing" contains untruthful statementsof fact, you do have some recourse.

Most state laws have a very specific definitionregarding what is defamatory.  Generally, statements of fact that imputean inability to perform or a lack of integrity in performing employment dutiesor similar statements about a business or profession are considered libelous. However, expressing an opinion is not.  For example, statements that youcheated them or incorrectly installed equipment are factual statements, and iffalse, are defamatory. On the other hand, a statement that you are a lousytechnician is an opinion and cannot be considered defamatory.

Unfortunately, not all defamatory statements areactionable.  In some states, corporations and other businesses areconsidered "public figures" under libel law, and are thereforesubject to a higher burden of proof. In public figure cases, it is not enoughthat the statement is false, you must also prove that the statement was madewith malice – that is, with an intention to harm your business.

When our clients have had experiences similar toyours, we will generally send a letter to the person doing the bashing,demanding that he or she retract the statements and threatening a lawsuit. Mostof the time this works, but on one occasion, our threat led to even furtherbashing. It took filing a lawsuit to reach a settlement.