The first sentence says there has been some controversy over adding synthetic fluoride to water supplies, and sadly this is true. What they are claiming is that there has not been enough controversy. Many others would say differently and say that it's been to much controversy, and that there shouldn't be any controversy at all because the amount of fluoride added to most water systems is in such low doses that you would have to drink over three times as much water as the recommend daily intake inorder to ingest enough fluoride for it to be toxic to you.
Odds are you would probably die of water poisoning before you would die of fluoride poisoning if just from drinking water.
The sentence says that water fluoridation is a serious issue. This is somewhat true, but only in the financial sense and whether or not water fluoridation is worth the cost. All other concerns are are the result of not understanding the science behind water fluoridation, as well as fear induced paranoia brought on by conspiracy theories and junk science regrading water fluoridation.
The last sentence states that fluoride, along with GMOs and vaccines rank among the "greatest crimes against humanity".
Besides the fact that these two things have nothing to do with water fluoridation, this isn't simply not true, it's actually quite the opposite.
Both GMOs and vaccines are not only safe, they have also been two of the most beneficial things for humanity by decreasing starvation and decreasing one's chances of dieing from an infectious disease.
Not only is this person trying to push the made up controversies surrounding water fluoridation, they are also trying to couple this with the made up controversies surrounding GMOs and vaccines to make it sound like they are all the same in a sense.
The only thing these things have in common is the fact that people believe they are bad for you and that they are part of some conspiracy, as well as the fact they all have been beneficial to our overall health.
Last, the picture in the screen shot itself claims that 98% of all European counties ban water fluoridation. This is not accurate. Most places in Europe do not ban water fluoridation, they just choose not too.