It's important to realise that everything can be faked on the internet!

Seriously, when I built the scores system this was the first "problem" I tried to tackle. How to make it legit, fair, honest? Only to conclude that there is no way to prevent people from posting fake scores.

Use the scores system with that in mind. Use it to keep track of your own scores. To compare with your friends, people you "trust".

I have long planned to add an abuse/flag icon to scores to allow the community to direct us to clearly fake scores. And it will be implemented one day. It's not like I don't care about people abusing the system. But as with anything on the internet, you just have to be realistic too. Short from filming your entire game there is just no way to validate if a score is valid.