It breaks the web. There are literally no real rules on how you use them, so you have a lot of things that will be confused with tracking (gclid,clickid,campaig

It breaks the web. There are literally no real rules on how you use them, so you have a lot of things that will be confused with tracking (gclid,clickid,campaign, etc). Even stuff that was originally tracking gets re-used. I've worked on systems where utm_medium=web and utm_keyword=socks were used to literally query the landing page for the user and effectively were the U in URL.