International friendlies tend to have a more relaxed atmosphere and near the end of 10-man Germany's 3-1 loss to Argentina, we saw that they can have more relaxed security as well. In the 89th minute, a joyous pitch invader jogged out to the center circle without so much as a single steward giving chase. The man was holding something in his hand, but used his free one to shake hands with Leo Messi.
The German crowd cheered when Messi went along with it instead of brushing the guy off as would (and probably should, so as not to encourage anymore invaders) most other footballers. Messi was all smiles as the guy celebrated his personal victory and was then escorted away in rather polite fashion.
Messi had a penalty saved by Germany's backup keeper Marc-Andre ter Stegen when starter Ron-Robert Zieler was sent off in the 30th minute, but made up for it with a goal in the 52nd minute.
UPDATE: Apparently Messi has made a habit of this kind of thing this summer. During a match against Mexico in June, Messi signed an autograph for a young pitch invader (thanks to @fcbfandrivel)...
Video via 101gg