Can I be sued?

The below does not constitute legal advice, does not form an attorney-client relationship, and should not be relied upon to take or refrain from taking any action.

Step One: You're only a trademark owner if you use a mark in commerce -- that is, if you offer to sell YOUR own goods branded with the alleged mark. Your offers for sale could be direct to consumers or through licensees and the goods may be manufactured for YOU by someone else.

Offering to sell someone else's branded goods does not provide you with any trademark rights. Likewise, simply registering a mark with the US Trademark Office provides you with no rights to the mark. What one "registers" is the common law rights created by the mark owner by its use of the mark in commerce. No use = no rights. In fact, you cannot lawfully register a mark unless it is "used in commerce" -- a phrase with a very particular meaning in trademark law. Falsely asserting to the US Trademark Office that YOU are using a mark in commerce is a misdemeanor.

So ... assuming that you're in the business of selling YOUR product that is branded with the mark that you claim is "well known worldwide" then you can -- indeed must -- take action to prevent others from selling related goods or services branded with your mark or any marks that are confusingly similar to your mark. Your registration of your mark with the US Trademark Office will provide you with significant advantages in any litigation and can be persuasively wielded in pre-litigation discussions with the alleged infringers.

Trademark owners have an affirmative duty to take action to prevent infringing uses of their marks. If a trademark owner takes no action when he or she knows, or has reason to know, that an infringement is occurring then the owner's right to prevent that unlawful may be waived -- or, worse, the owner's trademark rights in its mark may be deemed abandoned (permitting anyone to use the mark).

If you intend to enforce your trademark rights then you need to discuss the matter with an experienced trademark attorney. Do not send any cease and desist letters yourself. Such letters, wrongly worded, can land you in a far-away court and unprepared (financially and otherwise) to respond to the alleged infringer's claims.

You question doesn't state that you're actually selling products with this famous worldwide mark on products or using it for services, and indeed, your state that you want to sell products in the U.S. as if you're not now doing that. Apparently you've gotten the mark registered in the U.S., so you presumably provided the U.S.P.T.O with some specimens of your use, so your question is confusing.

You could theoretically stop other users if they're infringing, and in fact as has been pointed out, you're obligatred to police unauthorized uses of your mark, but without getting more facts about your use, your mark's registration, and the allegedly infringing use of other distributors, the question of whether you have the legal right to try to stop anyone else can't be answered.

Disclaimer: This response should not be relied on for any purpose, as each situation is unique, no evaluation is possible without a complete review of all the facts and documents involved in any legal question, and each state has its own laws. This response does not create an attorney-client relationship.

The answer to the question "Can I be sued" is always YES, the issue is whether or not the suit will be successful.

You have already received good advice - please speak with a trademark attorney for further guidance.