I urge you to speak with an intellectual property attorney, preferably one with  "cybersquatting" experience. You *may* have a cause of action, but it depends on the exact circumstances, which is why a consultation with a laywer is so important.It's been held in a number of cases that one party cannot "cybersquat" or otherwise fraudulently redirect web traffic from another entity to itself, to either confuse the marketplace and/or "extort" a payment to buy the webaddress. However, when a party is using a website which is legitimately connected to its business, that might not be improper. For example, say that you are the Global Health Agency and the other entity is the Global Health Advisor; let us postulate that they have legitimately been using that name and they did not come up with the name specifically to cause confusion, but rather this is simply the fact that there are only so many logical names for entities involved in world health--you both ended up with similar ones. In that case, their using www.gha.or or www.globalhealth.org or etc. would probably be legitimate.On the other hand, if the name of their organization is "International Medical Advisory," then if they suddently purchased the domain www.globalhealth.com, that looks suspicious and could support a cause of action. The facts, in a case  like this, are all important.