I know a businessman who has received a LOT of mileage off of using "Dr." and "Ph.D." with his name - in fact he puts it front and center. However, it turns out that he never had more than two years of undergraduate work. Is there any teeth behind either of these titles, or is it just a matter of how many you can deceive for how long?
I know a businessman who has received a LOT of mileage off of using "Dr" and "PhD" with his name
I don't know which country we are talking about, but at least in Austria, Germany, and Switzerland "Dr." is a protected title, and pretending you have one when you don't is a criminal offence. In Austria, for instance, this is part of federal law (see also the Bundesgesetzbuch). I would assume that PhD is also a protected title in the US and Great Britain.
However, note that this law explicitly only covers "pretending to have a doctoral degree", which leaves some wiggle room. For instance, there is an notorious Austrian bus company called "Dr. Richard", where the "Dr." are officially just the initials of the name of the owner (Dragan Richard).
In the United States, the appropriate response to such a fabrication is to call the person out and shame them publicly. Once this happens, it is often quite effective, as attested to by infamous cases such as Marilee Jones being forced out of MIT. The same goes for people claiming to have proper credentials based on a "diploma mill" degree.
This will not, of course, stop a person who has no shame, but it will at least make their life harder and make it difficult for them to maintain their lies with people who actually care about qualifications.
In Portugal, due to historical reasons, almost anyone that has some education can (high school degree suffices), and sometimes demands, be referred to as 'Doctor' (Dr.), although in Portugal as well, the title is legally protected today. So ultimately it depends on the cultural context and whether the person you refer to goes beyond putting the letters 'Dr.' in business cards, or actively lying about his/her qualifications.
In Portugal, up to recent times after the completion of an undergraduate degree – except in architecture and engineering – a person was referred to as doutor (Dr.) – male or doutora (Dra.) – female. […] Nowadays Portugal is a signatory to the Bologna process and according to the current legislation the title of Doctor (doutor, doutora) is reserved for graduate holders of an academic doctorate.
In the US, I know that when you apply for a job and post your credentials, most basic background checks will at least ensure you graduated from said school with what degree you put on it. Lying about it, depending on what job, will probably result in you getting fired or potentially arrested depending on who you lied to.
It is also not uncommon to find mistranslations from spanish regarding the term 'Professor' (usually holding a PhD title), since the word for 'teacher' is the same in Spanish for both, altought the second does not generally require to be a doctor. The same happens with "Associate Professor" and "Full (time) Professor". Further, some medical practicioners are always regarded as doctor whether or not they have a Phd or even some sort of postgraduate or advanced studies. As long as the misinterpretations are not due to malign intentions, this does not suppose a matter to worry much about, but it is always a good idea to find out more about the context where the term is forged. Also be on the look for slight transliterations such as 'Doctorand' or 'PhDc' (PhD candidate) that people generally use when they are in the final stages of attaining the title, but not officially there yet, such as when right before submitting the dissertation or after doing so, while the academic authorities issue the title with the seals and all. But no, the title Ph.D. is not meaningless at all (neither all of the others) and it is generally respected worldwide. There is always of course some trouble with homologation across regions, universities, countries or supranational areas, which is one the the issues that the Bologna process is struggling to deal with across European member states. Some other treaties to be on the look for is the Hague Convention Abolishing the Requirement of Legalisation for Foreign Public Documents, a.k.a. "the Apostille Convention", or the "Apostille Treaty".