i use blockchain.info as my bitcoin wallet
can they still spy on me with that?
Going through the web make you even more traceable. However if you can register without giving private information, use encrypted email and vpn to connect, you may be able to negate that part.
Still, whenever you interact with websites, wallet to a wallet, you create traceability. You need to wear gloves for everything and the best is to avoid doing anything traceable. The level of anonymity you really need depend on what you're doing and who/where you are, however.
Agree on this.
If you want to do something illegal, it depends on what extent.
In example, if you sell weed, unless you enter the "thousands dollars per month" realm, I don't think that NSA will begin to check your connection, and until you create new Bitcoin addresses, you are safe: nobody can find how you get paid.
But if you plan to do something worse, like, I don't know, importing 300000$ of drugs, I would never, ever use my HOME connection to get my payment throught Bitcoin.
I would use a completely separate device for that purpose, and use it on an open wifi or only turn it on with mobile connection to effect the transfer, then turn it off immediately.
And even then, I would leave that device FAR from my home, because each and every device has its own ID and even if you connect from a public place with your CrapPhone, then you bring that CrapPhone at home, they will identify that it was THAT CrapPhone that connected to THAT wifi and effected THAT transfer. It's like a hot potato.
You wouldn't be safe anyway.
The conclusion is that BANKNOTES are FAR more anonymous than Bitcoin.
If you like Bitcoin because it's anonymous, you are on the wrong way: revert to banknotes.
Bitcoin is only PRIVACY SAFE, but nothing more.