NO. In a democracy the people can choose to limit the state's authority. I can be for a government that allow free speech(even for them who speeks against the government) and a lot of personal freedom, I can be for a governement that allow its citizins to be a gay nazi jew libertard, if thats what they want to be. That government can also be pro-taxes, which i think is a good thing, and i will support it. BUT i will not support a government that kills its citizens, limits its citizins personal freedoms substantially, and is against free speech.
And yet, if the majority decides not to limit its authority, or decides to limit personal freedoms, free speech, and even be ok with killing its citizens, then you're SOL, because, as Mike has said, you have accepted its authority, and thus must submit to ALL of its authority.
Now may you that its still a democracy, and everyone is then subjected to superior and unlimited authority of the majority. But you know what? You would still be that in a libertarian society, no matter how anarchistic it is. If the majority decides something, they decide something. No matter how much you stand on your ridiculous moral high ground, they would still get their will. You would still be subject to the "tyranny" of the majority.
And this is why I, and likely Mike, as well as other anarchist, think that libertarians still don't go far enough. As Mike said in his post, those who give any authority to government by default agree to submit to all of it. So, you are right, libertarians would still have the problem of allowing a majority to decide some things, and would still end up having issues to being "subject to the 'tyranny' of the majority." That's why we're not libertarians. (P.S. We agree with that part, and we don't know whom you're talking to with that paragraph).