Biggus: that's a good point, about what has been signed up for via a legal obligation. Whether or not MPA is the platform you use to meet that obligation is a policy level decision.
OT, but possibly of interest For Duncan:
If you go to
www.secretservice.gov, you can find a lot of ways to easily contact the security folks if you overhear or suspect a threat against the President, a judge, a Senator, ambassador, or a foreign official who may visit the US. You call the local field office, or a contact number.
If you were in a pub, say, in London, and heard someone discussing (hypothetical here) the First Sea Lord's upcoming visit to Washington (to discuss Naval stuff with his US counterpart, or some conference) and didn't like the tone of voice regarding "the surprise he was in for" or something that made the hair on the back of your neck stand up ... you can (this is all publicly available information) contact someone at a field office.
United States Secret Service: Field Office Contact Information
For each of the 50 states, they are listed at the link.
I was interested to find that contact numbers are listed for some of our allies.
CANADA
-MONTREAL 1-514-939-8400 x2092
-OTTAWA 1-613-688-5460
-TORONTO 1-416-640-8661
-VANCOUVER 1-604-689-3011
FRANCE (PARIS) 011-331- 4312-7100
FRANCE (INTERPOL / LYON) 011-334-7244-7198
GERMANY (FRANKFURT) 011-49-697-535-3763
ITALY (ROME) 011-390-64-674-2736
NETHERLANDS (EUROPOL / THE HAGUE) 011-3170-353-1533
SPAIN (MADRID) 011-34-91-587-2202
UNITED KINGDOM (LONDON) 011-44-20-7894-0846
The procedure would be: call and advise the PoC of the nature of what you think is a threat.
Example: "Some wag posted the following on the internet that I think is a threat to the (President / First Sea Lord visiting the US / Justice Stephens, whomever), here's the URL address ..."
What one expects is that such is then included in leads that the Secret Service would triage and decide to pursue, or let slide as "not a threat."
Sorry, not about SAR, or MPA, but who knows what one will hear about?