Using Talis and Tor likely invites more scrutiny from the government as they now know you have something to hide.
This is true and is a trigger to get on the NSA list.
Google search for Tails is one avenue used and downloading can be seen by PRISM and reported to the NSA.
I use DuckDuckGo for search and only visit and download while behind a VPN.
An ISP can see the use of Tails and TOR but with the widespread use of VPN's for business access the ISP now has a large volume to sift through and typically don't but they do log it in case of being suppeneod for records.
One other weakness is the exit TOR server but I think this has been addressed by later versions of Tails.
Being on the NSA list can be triggered by so many means that they can't chase down all these people so I don't worry about them knocking on the door just for my effort to have privacy.
The exception is that if I was busted for something pretty major or added to a specific list such as known terrorist list and then AI tied me back to the NSA list the I would be concerned.
With Snowden exposure and the last Administration using the NSA to spy on private citizens we are all at risk.
Another safeguard I use is to use a Swedish VPN and Mail service due to their strict laws and the inability for our Government to get records especially when a service there may not even keep logs.
Bottom line is there is nothing 100% but you can sure make it difficult for them to violate your privacy.
Another safe measure is to use a cryptocurrency for payments and only use a vendor on the other end that also requires the use of TOR or Swedish based servers.