[davidjohnstone]

Interesting, I didn't know you could do that. When I write "I'm not saving the phone number you enter" I mean to convey the idea that I'm not doing anything else with that number. As far as I know, the number and any derivative products of that number only exists inside the request context and are not stored in any way. There could be bugs, or I could be lying, but I'm not doing anything underhanded like that.

[daniellarusso]

If you are using POST over https, that should be fine.

But, if it is GET requests in the URL over http, yeah, that is leaving a trail.

Any 3rd party JS analytics has access to everything, though.