Nation-states counter illegal content in the Internet not only by expanding the extraterritorial application of their criminal law but also by attempting to insulate the Net from illegal foreign content. The project demonstrates that this type of blocking order as applied to access providers in a country’s own territory prevents citizens from accessing illegal content in the Internet only to a limited extent and only with serious infringements of liberty (especially the privacy of telecommunications).

The pre­ven­tion and pro­sec­u­tion of crime com­mit­ted in the In­ter­net is dif­fi­cult be­cause the com­pet­ence of na­tion­al se­cur­ity agen­cies ends at their na­tion­al bor­ders. For this reas­on, na­tion-states can­not ef­fect­ively counter il­leg­al con­tent on for­eign serv­ers. Hence, many coun­tries at­tempt to in­su­late their na­tion­al ter­rit­ory against il­leg­al con­tent in the In­ter­net: if data saved on for­eign serv­ers can­not be re­moved, tech­nic­al block­ing meas­ures should at least pre­vent cit­izens from ac­cess­ing it.
In Ger­many, too, or­ders for block­ing ac­cess to such data have already been is­sued by agen­cies re­spons­ible for reg­u­lat­ing the me­dia. In prac­tice, however, these "block­ing or­ders" were not very ef­fect­ive, and their re­cep­tion was pre­dom­in­antly neg­at­ive. For this reas­on, the Com­mis­sion for Pro­tec­tion of Minors in the Me­dia (Kom­mis­sion für Ju­gendmedi­ens­chutz), which is re­spons­ible for block­ing or­ders in Ger­many, com­mis­sioned the Max Planck In­sti­tute for For­eign and In­ter­na­tion­al Crim­in­al Law to provide an ex­pert leg­al opin­ion on point.
The ob­ject­ive of the ex­pert opin­ion and the res­ult­ing pro­ject was a com­pre­hens­ive study of the leg­al­ity of block­ing or­ders in the In­ter­net ac­cord­ing to Ger­man law. With an eye to­wards fu­ture re­forms, the pro­ject fo­cused on the rel­ev­ant in­fringe­ments of fun­da­ment­al rights. The sys­tem­at­ic ex­am­in­a­tion was based on our own pre­par­at­ory work and ana­lyses, on an as­sess­ment of the case law, and on aca­dem­ic lit­er­at­ure in law and tech­no­logy. Fur­ther­more, the Dresden Uni­versity of Tech­no­logy pre­pared an ex­pert opin­ion, like­wise com­mis­sioned by the Com­mis­sion for Pro­tec­tion of Minors in the Me­dia, on the rel­ev­ant tech­nic­al is­sues.
The study showed that the ex­ist­ing reg­u­la­tions for block­ing or­ders in Ger­many are in­ad­equate. Already at the le­gis­lat­ive level, the fact that mul­tiple agen­cies may is­sue block­ing or­ders proves to be det­ri­ment­al, and the many re­fer­rals in the stat­utory pro­vi­sions to oth­er pro­vi­sions lead to en­force­ment prob­lems. The main prob­lem with block­ing or­ders, however, is that they lead to in­fringe­ments of fun­da­ment­al rights. The most im­port­ant of these in­clude the ac­cess pro­vider’s rights to free­dom of oc­cu­pa­tion­al choice and to prop­erty, the con­tent pro­vider’s right to free­dom of ex­pres­sion, and the user’s right to free­dom of in­form­a­tion. Also prob­lem­at­ic is the fact that in many cases the im­ple­ment­a­tion of block­ing or­ders also en­croaches upon the user’s right to tele­com­mu­nic­a­tion pri­vacy through re­port­ing of the re­ques­ted IP ad­dresses and URLs. This fun­da­ment­al right pro­tects not only the con­tent but also the prox­im­ate cir­cum­stances of the com­mu­nic­a­tion; most block­ing tech­no­lo­gies must en­gage in blanket con­trol of these cir­cum­stances in or­der to pre­vent ac­cess to spe­cif­ic data. The cur­rent leg­al situ­ation does not, however, per­mit block­ing or­ders that in­fringe upon tele­com­mu­nic­a­tions pri­vacy as pro­tec­ted by Art. 10 of the Ger­man Ba­sic Law and § 88 of the Tele­com­mu­nic­a­tions Act. At present, this elim­in­ates all of the more soph­ist­ic­ated block­ing or­ders that in­volve the ana­lys­is of IP ad­dresses, port num­bers, URLs, or con­tent data. Only the – less ef­fect­ive – ma­nip­u­la­tions of do­main names on the cor­res­pond­ing serv­ers and the elim­in­a­tion of entries on the hit list of search en­gines are per­miss­ible.
Due to these in­fringe­ments of fun­da­ment­al rights and in­ter­ven­tions in the tech­nic­al in­fra­struc­ture of the In­ter­net, it is ques­tion­able wheth­er block­ing or­ders in glob­al cy­ber­space are prac­tic­able. If the le­gis­lature truly in­tends to fa­cil­it­ate more ef­fect­ive and trans­par­ent na­tion­al pro­tec­tion against il­leg­al con­tent in the In­ter­net, it will be ne­ces­sary to en­gage in a ser­i­ous dis­cus­sion of the tech­nic­al con­cepts re­gard­ing the “ter­rit­ori­al­iz­a­tion of the In­ter­net” in open so­ci­et­ies, of the vari­ous leg­al al­tern­at­ives, and of the lim­it­a­tions on these al­tern­at­ives as dic­tated by the per­son­al liber­ties of cit­izens.