[realityking]

You can insult Theresa May as much as you like, you won't charged under this law - as long as May is not in Germany when you do so.

The law only universally applies to Heads of States, not Heads of Governments.

[allendoerfer]

You can be charged under different laws, though (§ 185 - § 200 StGB [0]). There is a higher threshold of what public figures have to tolerate, still like everybody else, foreign politicians can sue you under these paragraphs for insulting them.

[0] https://www.gesetze-im-internet.de/englisch_stgb/englisch_st...