Independently of the methods used to process that data, the API data -LSB-...] are therefore not sufficient to attain with comparable effectiveness the public security objective pursued by the agreement envisaged» (para. 214). (europeanlawblog.eu)
Following a classical reasoning on the assessment of the proportionality of the interference (see for example Schwarz, C ‑ 291 / 12, para. 53), the AG explains that the proposed agreement «must also consist of the measures least harmful -LSB-...] while making an effective contribution to the public security objective pursued by the agreement envisaged». (europeanlawblog.eu)
The former stated at para 3.10: «There must be «a reasonable relationship of proportionality between the means employed and the legitimate objectives pursued by the contested limitation» a measure that will satisfy the proportionality test only if three criteria are satisfied: the legislative objective must be sufficiently important to justify limiting of fundamental rights; the measure designed to meet the legislative objective must be rationally connected to that objective. (newlawjournal.co.uk)