urls often contain tracking information added to the end of them. when you are linking articles, stuff like the "utm_source" and "fbclid" sections allow people to track where you got the link from and how you are spreading it. this allows cops & corps to map out social groups.
while you can remove that stuff by hand, there's a firefox/chrome addon called "neat URL" that comes with an existing blocklist that automatically cleans off a lot of that stuff.