Literally every single online company is giving your data to law enforcement, often including real-time access.

This is the thing that Snowden leaked.

Facebook, Gmail, your cellular provider, Amazon, Credit Card companies, your bank, etc. They're all systems that law enforcement intelligence can access, probably without a subpoena (a business can choose to give up business records since they own them, you don't own 'your data').

If you're doing something online, or on your phone, you should pretend that there's a law enforcement officer sitting and reading over your shoulder because they effectively are. If they ever has cause to look at you they'll pull the history of your account (possibly limited to 30 days back but there's no guarantee of this) and see everything you've ever written and posted included things that you deleted.

If you did anything illegal they can use this information to start a new investigation, in addition to whatever investigation that led them to your account. This can allow them access to even more accounts.

So, if you're using any commercial service that holds your data, you should assume that a law enforcement officer is combing through your information and trying to find something to charge you with.

You should not use commercial services if you're in the US. I know I'm preaching to the choir in this community, but sometimes people need to see it written in black and white.