mamadeb

Extra apostrophes are a bane. Due to a strong English language presence (and maybe some evil, twisted notion of "cool") some people here include apostrophes into German possessive cases, which just isn't done, the only time there are apostrophes present is when something ends on an "s" and you can't add another "s" so an apostrophe is added instead of the letter. And if that alone wasn't bad enough some people they also randomly insert them into plurals formed with an s (which thankfully isn't the most common way in German to form a plural, so it's not quite as rampant) like in your example.