Yes. Especially if you say something negative and disparaging about the company or its employees.In an “at will” employment context, you can be fired for any reason or no reason as long as it is not a discriminatory reason. Casting the company or its employees in a negative light on the Internet will definitely be grounds for termination.As a general rule, do not say anything at all about your employer or co-workers on your social media sites unless you have been expressly authorized or asked to do so by the company. Don’t assume that because you aren’t connected or linked to the employer on that site that the company won’t see what you are posting. Instead, assume that everything being posted online is public and permanent and that you shouldn’t being saying anything that you would not say directly to your employer.