Yes, but you will need to first correlate connection data from a ton of anonymous IPs, and then send tough guys to the site to check everybody's passports at a gunpoint.
Or you just correlate the data with known locations as the NYT did in the article when they tracked the inauguration singer by knowing where she was on a single day.
Even if person had an anonymous SIM it would be trivial to identify them by the locations where they spent most of their time.