Yes, it is unlawful to sell a knock-off. Even if you believe it is authentic, you can still get sued by the maker for trademark infringement.

Need some details for creating a disclaimer on a digital ad using competitors trademarked names

Your goal is to eliminate any likelihood of confusion with your competitors. Contact an experienced trademark attorney, who will advise you how to...

Do I need an IT attorney? Got letter for infringement for selling an Adobe software on Amazon.

Talk to an attorney. You attorney can assess the likelihood of them suing and advise you accordingly. Do not try to negotiate this yourself.

About streaming a net-radio station live during a live videogame broadcast on Twitch.tv

If you are intending to stream music to the public, you need a license from the copyright holder. Typically, you would get one through ASCAP, BMI...

Create a board or card game based off the idea of a similar board, card or video game.

If what you create is substantially similar to the game you are imitating, you could be liable for copyright infringement. Substantial similarity...

Can a secondhand shop sell knock-off products (clothing, handbags, shoes) legally?

Selling knock-off products will earn you a lawsuit at the least and you might get the goods seized by Federal agents. Makers of high end products...

I started a business with my name as the name of the company. I need to find out about trademarking my name/cease and decist

This issue depends on the conditions under which you sold the company. You need to talk to your business attorney about the contractual issues.

Is it possible to patent the process/use of selling two skin care products with a two specific main ingredients?

Methods of treatment can be patentable. It would be important to show that use of ingredient A and the ingredient B gives rise to a result that is...

Question about photo/image copyright laws?

When you use photographs taken by another, you are infringing their copyrights in the photograph. Many photographers and stock photo companies use...

So long as the rebranding does not give rise to a likelihood of confusion as to the source of the product, there should not be a problem. If you...