How can I use the word "zip" on a paintball product if http://www.gtzip.com already has "Zip庐"?

It seems unreasonable that big companies like Coke gets to trademark common slogans like "Its the real thing" and GTZip locks in "zip" making new little companies afraid of being sued if they dare use these words. Do I really have to hire a lawyer for thousands of dollars to protect myself?

I am not a practicing trademark or patent attorney but I have been interested in this sort of thing since the WTO protests in Seattle. Corporate intellectual property rights is the new Imperialism. Revenues from trademarks, patents and copyrights on everything from music to seeds now account for 40% of American "exports" and is growing rapidly. Powerful countries used to discover, develop, and extract resources from abroad using indigenous labor. The threat to that system was "nationalization" (Egypt, Cuba, etc.) Nowadays powerful corporations attract the best minds from abroad, then claim the rights to their ideas. The current threat is "pirating" (Napster, China, etc.) So, the system takes the 庐 very seriously.
I visited GTZIP website http://www.gtzip.com and see that they are a plastic bag company. (I expected a drug company or drink company - like Red Bull.) Therefore, Zip庐 applies to plastic bags. In theory, you should be able to use "zip" for any paintball products except bags. However, gigantic plastic corporations like GTZIP have roomfuls of lawyers working for them who are necessarily very aggressive. They must prevent genericide. They constantly monitor all media. The internet is the easiest place for them to find use of, or reference to, their registered terms. The irony is that you must assume that your posting of this question has already been noted and you are now on their radar. And don't think that being a "little guy" will protect you - check out the case of Scotts Miracle Grow against TerraCycle. The federal lawsuit pitted Scotts, a $2.7 billion business with a 51 percent share of the U.S. lawn and garden products market, against TerraCycle, a Trenton company with $1.5 million in annual sales operating out of a graffiti-covered warehouse. Guess who won.

I doubt this company has the rights to the word "zip". Depending on the country you are in, I'd contact your government body that manages trademarks and patent law. They would surely have a free hot-line to assist you with this sort of enquiry.

Good luck