It was probably mostly the volume since I had a random number generator for intervals (not to disguise, just out of courtesy). It was not exactly a lot of traffic (compared to what they receive anyway, but it must have been too long and (still) too regular.

Oh well, best regards, -gjb-

Automated requests may lack browser identification as well (if request to webpage, not web service).

Of course, a best randomized disguise would be randomizing across internet domains but that won't be practical for most (law-abiding) people. Temporal randomization might not mean much if the time interval is too short, especially when shorter than the sampling intervals in which the series are analyzed.